Test Directory - Understand Your Tests.

Salivary Cortisol (Five Specimens), MS (Endocrine Sciences)

Expected Turnaround Time

5 - 9 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

SCA2 (ATXN2) Genetic Testing (Repeat Expansion)

Special Instructions

This assay is not currently available in New York state.

Expected Turnaround Time

2 - 4 weeks

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Specimen Requirements

Specimen

Whole blood

Volume

4 mL

Minimum Volume

1 mL

Container

Lavender-top (EDTA) tube

Collection

Draw blood into EDTA tube.

Storage Instructions

Ship ASAP, but stable up to 5 days post-collection at room temperature. Do not freeze.

Stability Requirements

Temperature	Period
Room temperature	5 days
Refrigerated	5 days
Frozen	Do not freeze

Causes for Rejection

Frozen blood EDTA tube

Test Details

Use

Spinocerebellar ataxias (SCAs), and episodic ataxias are the most common types of autosomal dominant cerebellar ataxias (ADCAs). SCAs are numbered based upon their time of identification. SCA3 is the most common type of SCA worldwide, followed by SCA2, SCA1, and SCA6. Some of the complicated forms have not been given a SCA number, like Dentatorubral Pallidoluysian Atrophy (DRPLA). Anticipation can be observed in the autosomal dominant ataxias in which CAG trinucleotide repeats occur. Anticipation results from expansion in the number of CAG repeats with transmission of the gene to subsequent generations. Most ADCAs have an overlap in clinical presentation, which makes it hard to differentiate. The most frequent clinical symptoms in all ADCAs are progressive adult-onset gait ataxia (often with hand dysmetria), and dysarthria associated with cerebellar atrophy. The episodic ataxias are characterized by periods of unsteady gait and often associated with nystagmus or dysarthria. Myokymia, vertigo, or hearing loss may occur in some of the subtypes. Permanent ataxia and even cerebellar atrophy may result late in the disease course.

Limitations

This test was developed and its performance characteristics determined by LabCorp. It has not been cleared or approved by the Food and Drug Administration.

Methodology

Repeat-Primed PCR (QP-PCR)

Scabies Examination

Expected Turnaround Time

2 - 6 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Related Information

Specimen Requirements

Specimen

Submit skin scrapings between two glass slides rubber-banded together, or place dry scrapings in a sterile screw-cap container.

Container

Slides or screw-cap container

Collection

Place a drop of mineral oil on a sterile scalpel blade. Scrape a newly-developed papule vigorously six or seven times to remove the top of the papule. Transfer the scraped material mixed with oil to a glass slide, and place a second glass slide over the first. Rubber-band the two slides together.

Storage Instructions

Maintain specimen at room temperature.

Causes for Rejection

Inadequate labeling

Test Details

Use

Detection of the itch mite that causes scabies in humans

Methodology

Microscopic evaluation

Secobarbital, Serum or Plasma (Forensic)

Synonyms

Seconal®

Expected Turnaround Time

5 - 7 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Specimen Requirements

Specimen

Serum or plasma

Volume

5 mL

Minimum Volume

1.2 mL

Container

Red-top tube or green-top (heparin) tube. Gel-barrier tubes are not recommended.

Collection

Serum or plasma should be separated from cells within two hours of venipuncture. Submit specimen in a plastic transport tube.

Storage Instructions

Submission/transport (<3 days): Room temperature. For storage beyond three days, specimen should be refrigerated or frozen.

Patient Preparation

Trough levels are most reproducible.

Causes for Rejection

Gel-barrier tubes

Test Details

Use

Therapeutic drug management

Methodology

Gas chromatography/nitrogen phosphorus detection (GC/NPD); gas chromatography/mass spectrometry (GC/MS)

Reference Interval

1.0−5.0 µg/mL

Selenium, Whole Blood

Expected Turnaround Time

2 - 4 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Specimen Requirements

Specimen

Whole blood

Volume

2 mL

Minimum Volume

0.6 mL

Container

Royal blue-top (EDTA) tube; submit original tube.

Storage Instructions

Maintain specimen at room temperature.

Stability Requirements

Temperature	Period
Room temperature	14 days
Refrigerated	14 days
Frozen	14 days
Freeze/thaw cycles	Stable x3

Causes for Rejection

Clotted specimen

Test Details

Use

Monitor exposure to selenium; detect selenium deficiency

Limitations

This test was developed and its performance characteristics determined by LabCorp. It has not been cleared or approved by the Food and Drug Administration.

Methodology

Inductively-coupled plasma/mass spectrometry (ICP/MS)

Additional Information

Selenium toxicity may occur due to industrial exposures or through drinking water in some parts of the world. Toxic symptoms include garlic breath odor, thick brittle fingernails, dry brittle hair, red swollen skin of the hands and feet, and nervous system abnormalities of numbness, convulsions, or paralysis.¹ Selenium is produced as a byproduct of copper refining and is used in electronic semiconductors, as a decolorizing agent for ceramics and glass, and as a vulcanizing agent in the rubber industry. The essential nature of selenium in human nutrition is now beyond dispute. Multiple cases of selenium deficiency have been reported in patients receiving parenteral nutrition for longer than one week when no selenium was included in their formula. Deficiency has also been reported in severe malnutrition without parenteral nutrition. The syndrome has included painful weak muscles and acute or chronic congestive heart failure due to cardiomyopathy that is sometimes fatal. Other findings noted in some cases of selenium deficiency include erythrocyte macrocytosis, depigmentation of skin and hair, and elevated transaminase and creatine kinase levels.

Semen Analysis (AUA Guidelines), Postvasectomy

Synonyms

Postvasectomy Semen Analysis

Special Instructions

This test is not available at all locations and must be scheduled with the laboratory performing the test. Contact the laboratory prior to specimen collection. This test requires a freshly collected semen sample. If the sample is more than one hour old, please see Postvasectomy Sperm Evaluation, Qualitative [519020] for the presence or absence of sperm. This test does not include motility studies and can be conducted on any semen specimen that is submitted to LabCorp within 72 hours of collection.

Expected Turnaround Time

Within 1 day

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Specimen Requirements

Specimen

Semen

Volume

Entire ejaculate

Minimum Volume

0.5 mL

Container

Sterile screw-cap container

Collection

See Patient Instructions for Semen Collection.

Storage Instructions

Testing must begin within 60 minutes of specimen production. In the interim, the specimen should be kept at room temperature, but it is recommended that it be kept close to the body (inside a shirt or coat) to avoid temperature extremes during transport.

Stability Requirements

Temperature	Period
Room temperature	1 hour; keep sample close to body (inside shirt or coat) to avoid temperature extremes during transport. (stability provided by manufacturer or literature reference)
Refrigerated	Unstable (stability provided by manufacturer or literature reference)
Frozen	Unstable (stability provided by manufacturer or literature reference)
Freeze/thaw cycles	Unstable (stability provided by manufacturer or literature reference)

Patient Preparation

No special preparation. The American Urological Association recommends a waiting period of 8 to 16 weeks post vasectomy as the appropriate period for the first postvasectomy semen analysis.¹

Causes for Rejection

Specimens older than one hour; specimens contaminated with spermicidal material

Test Details

Use

Azoöspermia and <0.1x10⁶ nonmotile sperm per mL (or <100,000 nonmotile sperm per mL) are reliable indicators of vasectomy success. Incomplete ejaculation and/or incomplete collection of total ejaculate may cause false oligospermia (low sperm count) or false azoöspermia. If >0.1x10⁶ nonmotile sperm per mL (or >100,000 nonmotile sperm/mL) persist beyond six months after vasectomy, then trends of serial postvasectomy semen analyses and clinical judgment should be used to decide whether the vasectomy is a failure and whether repeat vasectomy should be considered.

Methodology

Macroscopic and microscopic semen examination

Semen Analysis, Basic

Special Instructions

This test is not available at all locations. Contact the laboratory prior to specimen collection. This procedure must be scheduled with the laboratory performing the test. The patient should have between two and seven days of sexual abstinence before producing the specimen. This test requires a fresh specimen; therefore, this procedure is available only at sperm testing facilities.

Expected Turnaround Time

2 - 6 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Related Information

Additional Specimen Types

Specimen Requirements

Specimen

Semen

Volume

Entire ejaculate

Minimum Volume

Approximately 0.5 mL

Container

Sterile screw-cap container

Collection

See Patient Instructions for Semen Collection.

Storage Instructions

Testing must begin within 60 minutes of specimen production. In the interim, the specimen should be kept at room temperature, but it is recommended that it be kept close to the body (inside a shirt or coat) to avoid temperature extremes during transport.

Stability Requirements

Temperature	Period
Room temperature	1 hour; keep sample close to body (inside shirt or coat) to avoid temperature extremes during transport. (stability provided by manufacturer or literature reference)
Refrigerated	Unstable (stability provided by manufacturer or literature reference)
Frozen	Unstable (stability provided by manufacturer or literature reference)
Freeze/thaw cycles	Unstable (stability provided by manufacturer or literature reference)

Patient Preparation

Patient should abstain from sexual activity for two to seven days prior to specimen collection.

Causes for Rejection

Specimens older than one hour; insufficient sperm (may prevent adequate estimate of percent normal morphology)

Test Details

Use

Diagnose male factor infertility, including oligozoöspermia, azoöspermia, asthenozoöspermia, and teratozoöspermia

Methodology

Manual macroscopic and microscopic examination of semen

Serotonin

Synonyms

5-HT, Serum
5-Hydroxytryptamine, Serum

Special Instructions

State patient's sex on the test request form.

Expected Turnaround Time

3 - 5 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Related Information

Special Chemistry

Specimen Requirements

Specimen

Serum, frozen

Volume

2 mL

Minimum Volume

1 mL

Container

Red-top tube

Collection

Separate serum from cells within 30 minutes of collection. Transfer to a plastic transport tube before freezing. To avoid delays in turnaround time when requesting multiple tests on frozen samples, please submit separate frozen specimens for each test requested.

Storage Instructions

Freeze

Stability Requirements

Temperature	Period
Room temperature	1 day
Refrigerated	1 day
Frozen	13 days
Freeze/thaw cycles	Stable x3

Patient Preparation

Monoamine oxidase inhibitor drugs should be discontinued for at least one week prior to sampling since they tend to increase the level of serotonin.

Causes for Rejection

Specimen not frozen; plasma specimen

Test Details

Use

Diagnose carcinoid syndrome

Limitations

In general, EDTA whole blood (as compared to serum) preserved with ascorbic acid will give values most representative of blood concentrations. Most (95%) of blood serotonin is found in platelets, thus a properly preserved whole blood sample is preferable. See Serotonin, Whole Blood [120089].

Methodology

High-pressure liquid chromatography (HPLC) with electrochemical (EC) detection

Reference Interval

Male: 21−321 ng/mL; female: 0−420 ng/mL

Additional Information

Serotonin is produced by cells of the APUD system, including the enterochromaffin (Kulchitsky) cells distributed through the mucosa of the gastrointestinal tract. Most serotonin in blood is usually concentrated in platelets, which release it during blood coagulation. Serotonin may be measured to confirm the diagnosis of carcinoid syndrome. The carcinoid syndrome is usually caused by primary carcinoids of the ileum, but the syndrome is occasionally caused by primary carcinoids of the stomach. Other organs give rise to carcinoids including pancreas, duodenum, bronchus, and ovary. Most patients with the carcinoid syndrome have hepatic metastases.

Severe Combined Immunodeficiency (SCID Including Omenn Syndrome): DCLRE1C (Artemis) for RS-SCID or SCIDA (Full Gene Sequencing)

Test Includes

This test covers all coding nucleotides of gene DCLRE1C (Artemis), plus at least two and typically 20 flanking intronic nucleotides upstream and downstream of each coding exon, covering the conserved donor and acceptor splice sites, as well as typically 20 flanking nucleotides in the 5′ and 3′ UTR.

Special Instructions

In cases in which a known mutation can be documented, the physician may prefer to order test 252723. Test orders must include an attestation that the provider has the patient's informed consent for genetic testing. See sample physician office consent form: Consent for Genetic Testing. In the case of family tests (ie, known mutations), please submit the result report of the first patient tested in the family (the index case), if not performed at a LabCorp facility. Other family members are subsequently tested for the specific mutation found in the first patient tested.

Expected Turnaround Time

28 - 35 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Specimen Requirements

Specimen

Whole blood; DNA is accepted (Call 800-345-4363 for DNA collection information.)

Volume

2 mL

Container

Lavender-top (EDTA) tube

Collection

Samples may be stored for brief periods at 4°C. Ship overnight at room temperature.

Storage Instructions

Maintain specimen at room temperature.

Causes for Rejection

Container broken or leaking; container not labeled or label not legible; improper anticoagulant

Test Details

Use

Confirm a clinical diagnosis of SCID; detect carriers; allow early diagnosis in family members

Limitations

This method does not reliably detect mosaic variants; large deletions; large duplications, inversions, or other rearrangements; or deep intronic variants. It may be affected by allele-dropout, it may not allow determination of the exact numbers of T/A or microsatellite repeats, and it does not allow any conclusion as to whether two heterozygous variants are present on the same or on different chromosome copies. Results of this test are for investigational purposes only. The performance characteristics of this assay have been determined by LabCorp. The result should not be used as a diagnostic procedure without confirmation of the diagnosis by another medically established diagnostic product or procedure.

Methodology

DNA sequencing

Reference Interval

Normal equals reference sequence or variants that are known or predicted to be benign; abnormal equals all other variants.

Additional Information

Severe combined immunodeficiency (SCID) is a recessively (X-linked or autosomal) inherited immune disorder characterized by severe lymphopenia and lack of adaptive immunity, leading to severe and persistent infections. Left untreated, SCID is typically lethal in infancy or childhood. T-cell lymphopenia is common to all forms of SCID, but may be initially masked by the temporary presence of maternal lymphocytes that have crossed the placenta during gestation. Levels of B cells and of natural killer (NK) cells vary depending on the genetic defect. Mutations in DCLRE1C (also known as Artemis) cause T-B-NK+SCID with autosomal recessive inheritance and account for about 1% of SCID overall. DCLRE1C-related SCID is also known as radiation-sensitive SCID, since it causes increased sensitivity of both bone marrow and skin fibroblasts to ionizing radiation. Mutations in DCLRE1C that show residual activity lead to Omenn syndrome, which can be distinguished from SCID by the presence of normal or elevated T-cell levels, elevated levels of serum IgE, and eosinophilia. In rare cases, B cells are also present; however, both B cells and T cells are oligoclonal and nonfunctional. Genetic testing can confirm a clinical diagnosis of DCLRE1C-related SCID and detect mutation carriers within affected families.

Severe Combined Immunodeficiency (SCID Including Omenn Syndrome): DCLRE1C (Artemis) for RS-SCID or SCIDA (Known Mutation)

Test Includes

All coding nucleotides of the specified gene(s), plus at least two and typically 20 nucleotides flanking each coding region.

Special Instructions

This option is available when the mutation is known and can be documented by the ordering physician. If the mutation cannot be documented, please order test 252492. Test orders must include an attestation that the provider has the patient's informed consent for genetic testing. See sample physician office consent form: Consent for Genetic Testing. In the case of family tests (ie, known mutations), please submit the result report of the first patient tested in the family (the index case), if not performed at a LabCorp facility. Other family members are subsequently tested for the specific mutation found in the first patient tested.

Expected Turnaround Time

21 - 28 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Test Details

Methodology

DNA sequencing

Severe Combined Immunodeficiency (SCID Including Omenn Syndrome): Eight-gene Profile (IL2RG, JAK3, RAG1, RAG2, IL7R, ADA, CD3D, CD3E) (Full Gene Sequencing)

Test Includes

This test covers all coding nucleotides of genes IL2RG, JAK3, RAG1, RAG2, IL7R, ADA, CD3D, and CD3E, plus at least two and typically 20 flanking intronic nucleotides upstream and downstream of each coding exon, covering the conserved donor and acceptor splice sites, as well as typically 20 flanking nucleotides in the 5′ and 3′ UTR.

Special Instructions

Test orders must include an attestation that the provider has the patient's informed consent for genetic testing. See sample physician office consent form: Consent for Genetic Testing. In the case of family tests (ie, known mutations), please submit the result report of the first patient tested in the family (the index case), if not performed at a LabCorp facility. Other family members are subsequently tested for the specific mutation found in the first patient tested.

Expected Turnaround Time

28 - 35 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Specimen Requirements

Specimen

Whole blood; DNA is accepted (Call 800-345-4363 for DNA collection information.)

Volume

2 mL

Container

Lavender-top (EDTA) tube

Collection

Samples may be stored for brief periods at 4°C. Ship overnight at room temperature.

Storage Instructions

Maintain specimen at room temperature.

Causes for Rejection

Container broken or leaking; container not labeled or label not legible; improper anticoagulant

Test Details

Use

Confirm a clinical diagnosis of SCID; detect carriers; allow early diagnosis in family members

Limitations

This method does not reliably detect mosaic variants; large deletions; large duplications, inversions, or other rearrangements; or deep intronic variants. It may be affected by allele-dropout, it may not allow determination of the exact numbers of T/A or microsatellite repeats, and it does not allow any conclusion as to whether two heterozygous variants are present on the same or on different chromosome copies. Results of this test are for investigational purposes only. The performance characteristics of this assay have been determined by LabCorp. The result should not be used as a diagnostic procedure without confirmation of the diagnosis by another medically established diagnostic product or procedure.

Methodology

DNA sequencing

Reference Interval

Normal equals reference sequence or variants that are known or predicted to be benign; abnormal equals all other variants.

Additional Information

Severe combined immunodeficiency (SCID) is a recessively (X-linked or autosomal) inherited immune disorder characterized by severe lymphopenia and lack of adaptive immunity, leading to severe and persistent infections. Left untreated, SCID is typically lethal in infancy or childhood. T-cell lymphopenia is common to all forms of SCID, but may be initially masked by the temporary presence of maternal lymphocytes that have crossed the placenta during gestation. Levels of B cells and of natural killer (NK) cells vary depending on the genetic defect. Mutations in IL2RG, JAK3, RAG1, RAG2, IL7R, CD3D, CD3E, or ADA account for >80% of cases. Genetic testing can confirm a clinical diagnosis of SCID, clarify the mode of inheritance, and detect mutation carriers within affected families.

Severe Combined Immunodeficiency (SCID Including Omenn Syndrome): RAG1 (Known Mutation)

Test Includes

All coding nucleotides of the specified gene(s), plus at least two and typically 20 nucleotides flanking each coding region.

Special Instructions

This option is available when the mutation is known and can be documented by the ordering physician. If the mutation cannot be documented, please order test 252470. Test orders must include an attestation that the provider has the patient's informed consent for genetic testing. See sample physician office consent form: Consent for Genetic Testing. In the case of family tests (ie, known mutations), please submit the result report of the first patient tested in the family (the index case), if not performed at a LabCorp facility. Other family members are subsequently tested for the specific mutation found in the first patient tested.

Expected Turnaround Time

21 - 28 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Test Details

Methodology

DNA sequencing

Severe Combined Immunodeficiency (SCID Including Omenn Syndrome): RAG1, RAG2, DCLRE1C (Artemis) (Full Gene Sequencing)

Test Includes

This test covers all coding nucleotides of genes RAG1, RAG2, and DCLRE1C (Artemis), plus at least two and typically 20 flanking intronic nucleotides upstream and downstream of each coding exon, covering the conserved donor and acceptor splice sites, as well as typically 20 flanking nucleotides in the 5′ and 3′ UTR.

Special Instructions

Test orders must include an attestation that the provider has the patient's informed consent for genetic testing. See sample physician office consent form: Consent for Genetic Testing. In the case of family tests (ie, known mutations), please submit the result report of the first patient tested in the family (the index case), if not performed at a LabCorp facility. Other family members are subsequently tested for the specific mutation found in the first patient tested.

Expected Turnaround Time

28 - 35 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Specimen Requirements

Specimen

Whole blood; DNA is accepted (Call 800-345-4363 for DNA collection information.)

Volume

2 mL

Container

Lavender-top (EDTA) tube

Collection

Samples may be stored for brief periods at 4°C. Ship overnight at room temperature.

Storage Instructions

Maintain specimen at room temperature.

Causes for Rejection

Container broken or leaking; container not labeled or label not legible; improper anticoagulant

Test Details

Use

Confirm a clinical diagnosis of SCID; detect carriers; allow early diagnosis in family members

Limitations

This method does not reliably detect mosaic variants; large deletions; large duplications, inversions, or other rearrangements; or deep intronic variants. It may be affected by allele-dropout, it may not allow determination of the exact numbers of T/A or microsatellite repeats, and it does not allow any conclusion as to whether two heterozygous variants are present on the same or on different chromosome copies. Results of this test are for investigational purposes only. The performance characteristics of this assay have been determined by LabCorp. The result should not be used as a diagnostic procedure without confirmation of the diagnosis by another medically established diagnostic product or procedure.

Methodology

DNA sequencing

Reference Interval

Normal equals reference sequence or variants that are known or predicted to be benign; abnormal equals all other variants.

Additional Information

Severe combined immunodeficiency (SCID) is a recessively (X-linked or autosomal) inherited immune disorder characterized by severe lymphopenia and lack of adaptive immunity, leading to severe and persistent infections. Left untreated, SCID is typically lethal in infancy or childhood. T-cell lymphopenia is common to all forms of SCID, but may be initially masked by the temporary presence of maternal lymphocytes that have crossed the placenta during gestation. Levels of B cells and of natural killer (NK) cells vary depending on the genetic defect. Mutations in RAG1, RAG2, or DCLRE1C (also known as Artemis) cause T-B-NK+SCID with autosomal recessive inheritance and account for about 4% of SCID overall. Mutations in RAG1, RAG2, or DCLRE1C that show residual activity lead to Omenn syndrome, which can be distinguished from SCID by the presence of normal or elevated T-cell levels, elevated levels of serum IgE, and eosinophilia. In rare cases, B cells are also present; however, both B cells and T cells are oligoclonal and nonfunctional. Genetic testing can confirm a clinical diagnosis of T-B-NK+SCID and detect mutation carriers within affected families.

Severe Combined Immunodeficiency (SCID Including Omenn Syndrome): RAG2 (Full Gene Sequencing)

Test Includes

This test covers all coding nucleotides of gene RAG2, plus at least two and typically 20 flanking intronic nucleotides upstream and downstream of each coding exon, covering the conserved donor and acceptor splice sites, as well as typically 20 flanking nucleotides in the 5′ and 3′ UTR.

Special Instructions

In cases in which a known mutation can be documented, the physician may prefer to order test 252704. Test orders must include an attestation that the provider has the patient's informed consent for genetic testing. See sample physician office consent form: Consent for Genetic Testing. In the case of family tests (ie, known mutations), please submit the result report of the first patient tested in the family (the index case), if not performed at a LabCorp facility. Other family members are subsequently tested for the specific mutation found in the first patient tested.

Expected Turnaround Time

28 - 35 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Specimen Requirements

Specimen

Whole blood; DNA is accepted (Call 800-345-4363 for DNA collection information.)

Volume

2 mL

Container

Lavender-top (EDTA) tube

Collection

Samples may be stored for brief periods at 4°C. Ship overnight at room temperature.

Storage Instructions

Maintain specimen at room temperature.

Causes for Rejection

Container broken or leaking; container not labeled or label not legible; improper anticoagulant

Test Details

Use

Confirm a clinical diagnosis of SCID; detect carriers; allow early diagnosis in family members

Limitations

This method does not reliably detect mosaic variants; large deletions; large duplications, inversions, or other rearrangements; or deep intronic variants. It may be affected by allele-dropout, it may not allow determination of the exact numbers of T/A or microsatellite repeats, and it does not allow any conclusion as to whether two heterozygous variants are present on the same or on different chromosome copies. Results of this test are for investigational purposes only. The performance characteristics of this assay have been determined by LabCorp. The result should not be used as a diagnostic procedure without confirmation of the diagnosis by another medically established diagnostic product or procedure.

Methodology

DNA sequencing

Reference Interval

Normal equals reference sequence or variants that are known or predicted to be benign; abnormal equals all other variants.

Additional Information

Severe combined immunodeficiency (SCID) is a recessively (X-linked or autosomal) inherited immune disorder characterized by severe lymphopenia and lack of adaptive immunity, leading to severe and persistent infections. Left untreated, SCID is typically lethal in infancy or childhood. T-cell lymphopenia is common to all forms of SCID, but may be initially masked by the temporary presence of maternal lymphocytes that have crossed the placenta during gestation. Levels of B cells and of natural killer (NK) cells vary depending on the genetic defect. Mutations in RAG2 cause T-B-NK+SCID with autosomal recessive inheritance and account for <3% of SCID overall. Mutations in RAG2 that show residual activity lead to Omenn syndrome, which can be distinguished from SCID by the presence of normal or elevated T-cell levels, elevated levels of serum IgE, and eosinophilia. In rare cases, B cells are also present; however, both B cells and T cells are oligoclonal and nonfunctional. Genetic testing can confirm a clinical diagnosis of RAG2-related SCID and detect mutation carriers within affected families.

Severe Combined Immunodeficiency (SCID Including Omenn Syndrome): RAG2 (Known Mutation)

Test Includes

All coding nucleotides of the specified gene(s), plus at least two and typically 20 nucleotides flanking each coding region.

Special Instructions

This option is available when the mutation is known and can be documented by the ordering physician. If the mutation cannot be documented, please order test 252472. Test orders must include an attestation that the provider has the patient's informed consent for genetic testing. See sample physician office consent form: Consent for Genetic Testing. In the case of family tests (ie, known mutations), please submit the result report of the first patient tested in the family (the index case), if not performed at a LabCorp facility. Other family members are subsequently tested for the specific mutation found in the first patient tested.

Expected Turnaround Time

21 - 28 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Test Details

Methodology

DNA sequencing

Severe Combined Immunodeficiency (SCID Including Omenn Syndrome): Three-gene Profile (IL2RG, ADA, IL7R) (Full Gene Sequencing)

Test Includes

This test covers all coding nucleotides of genes IL2RG, ADA, and IL7R, plus at least two and typically 20 flanking intronic nucleotides upstream and downstream of each coding exon, covering the conserved donor and acceptor splice sites, as well as typically 20 flanking nucleotides in the 5′ and 3′ UTR.

Special Instructions

Test orders must include an attestation that the provider has the patient's informed consent for genetic testing. See sample physician office consent form: Consent for Genetic Testing. In the case of family tests (ie, known mutations), please submit the result report of the first patient tested in the family (the index case), if not performed at a LabCorp facility. Other family members are subsequently tested for the specific mutation found in the first patient tested.

Expected Turnaround Time

28 - 35 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Specimen Requirements

Specimen

Whole blood; DNA is accepted (Call 800-345-4363 for DNA collection information.)

Volume

2 mL

Container

Lavender-top (EDTA) tube

Collection

Samples may be stored for brief periods at 4°C. Ship overnight at room temperature.

Storage Instructions

Maintain specimen at room temperature.

Causes for Rejection

Container broken or leaking; container not labeled or label not legible; improper anticoagulant

Test Details

Use

Confirm a clinical diagnosis of SCID; detect carriers; allow early diagnosis in family members

Limitations

This method does not reliably detect mosaic variants; large deletions; large duplications, inversions, or other rearrangements; or deep intronic variants. It may be affected by allele-dropout. it may not allow determination of the exact numbers of T/A or microsatellite repeats. and it does not allow any conclusion as to whether two heterozygous variants are present on the same or on different chromosome copies. Results of this test are for investigational purposes only. The performance characteristics of this assay have been determined by LabCorp. The result should not be used as a diagnostic procedure without confirmation of the diagnosis by another medically established diagnostic product or procedure.

Methodology

DNA sequencing

Reference Interval

Normal equals reference sequence or variants that are known or predicted to be benign; abnormal equals all other variants.

Additional Information

Severe combined immunodeficiency (SCID) is a recessively (X-linked or autosomal) inherited immune disorder characterized by severe lymphopenia and lack of adaptive immunity, leading to severe and persistent infections. Left untreated, SCID is typically lethal in infancy or childhood. T-cell lymphopenia is common to all forms of SCID, but may be initially masked by the temporary presence of maternal lymphocytes that have crossed the placenta during gestation. Levels of B cells and of natural killer (NK) cells vary depending on the genetic defect. Mutations in IL2RG, ADA, or IL7R are the most common causes of SCID, together accounting for about 70% of cases. Genetic testing can confirm a clinical diagnosis of SCID, clarify the mode of inheritance, and detect mutation carriers within affected families.

Severe Combined Immunodeficiency (SCID): ADA (Known Mutation)

Test Includes

All coding nucleotides of the specified gene(s), plus at least two and typically 20 nucleotides flanking each coding region.

Special Instructions

This option is available when the mutation is known and can be documented by the ordering physician. If the mutation cannot be documented, please order test 252475. Test orders must include an attestation that the provider has the patient's informed consent for genetic testing. See sample physician office consent form: Consent for Genetic Testing. In the case of family tests (ie, known mutations), please submit the result report of the first patient tested in the family (the index case), if not performed at a LabCorp facility. Other family members are subsequently tested for the specific mutation found in the first patient tested.

Expected Turnaround Time

21 - 28 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Test Details

Methodology

DNA sequencing

Severe Combined Immunodeficiency (SCID): CD3E (Known Mutation)

Test Includes

All coding nucleotides of the specified gene(s), plus at least two and typically 20 nucleotides flanking each coding region.

Special Instructions

This option is available when the mutation is known and can be documented by the ordering physician. If the mutation cannot be documented, please order test 252485. Test orders must include an attestation that the provider has the patient's informed consent for genetic testing. See sample physician office consent form: Consent for Genetic Testing. In the case of family tests (ie, known mutations), please submit the result report of the first patient tested in the family (the index case), if not performed at a LabCorp facility. Other family members are subsequently tested for the specific mutation found in the first patient tested.

Expected Turnaround Time

21 - 28 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Test Details

Methodology

DNA sequencing

Severe Combined Immunodeficiency (SCID): JAK3 (Full Gene Sequencing)

Test Includes

This test covers all coding nucleotides of gene JAK3, plus at least two and typically 20 flanking intronic nucleotides upstream and downstream of each coding exon, covering the conserved donor and acceptor splice sites, as well as typically 20 flanking nucleotides in the 5′ and 3′ UTR.

Special Instructions

In cases in which a known mutation can be documented, the physician may prefer to order test 252697. Test orders must include an attestation that the provider has the patient's informed consent for genetic testing. See sample physician office consent form: Consent for Genetic Testing. In the case of family tests (ie, known mutations), please submit the result report of the first patient tested in the family (the index case), if not performed at a LabCorp facility. Other family members are subsequently tested for the specific mutation found in the first patient tested.

Expected Turnaround Time

28 - 35 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Specimen Requirements

Specimen

Whole blood; DNA is accepted (Call 800-345-4363 for DNA collection information.)

Volume

2 mL

Container

Lavender-top (EDTA) tube

Collection

Samples may be stored for brief periods at 4°C. Ship overnight at room temperature.

Storage Instructions

Maintain specimen at room temperature.

Causes for Rejection

Container broken or leaking; container not labeled or label not legible; improper anticoagulant

Test Details

Use

Confirm a clinical diagnosis of SCID; detect carriers; allow early diagnosis in family members

Limitations

This method does not reliably detect mosaic variants; large deletions; large duplications, inversions, or other rearrangements; or deep intronic variants. It may be affected by allele-dropout, it may not allow determination of the exact numbers of T/A or microsatellite repeats, and it does not allow any conclusion as to whether two heterozygous variants are present on the same or on different chromosome copies. Results of this test are for investigational purposes only. The performance characteristics of this assay have been determined by LabCorp. The result should not be used as a diagnostic procedure without confirmation of the diagnosis by another medically established diagnostic product or procedure.

Methodology

DNA sequencing

Reference Interval

Normal equals reference sequence or variants that are known or predicted to be benign; abnormal equals all other variants.

Additional Information

Severe combined immunodeficiency (SCID) is a recessively (X-linked or autosomal) inherited immune disorder characterized by severe lymphopenia and lack of adaptive immunity, leading to severe and persistent infections. Left untreated, SCID is typically lethal in infancy or childhood. T-cell lymphopenia is common to all forms of SCID, but may be initially masked by the temporary presence of maternal lymphocytes that have crossed the placenta during gestation. Levels of B cells and of natural killer (NK) cells vary depending on the genetic defect. Mutations in JAK3 cause T-BSCID with autosomal recessive inheritance and account for about 7% of SCID overall. Genetic testing can confirm a clinical diagnosis of JAK3-related SCID and detect mutation carriers within affected families.

Severe Combined Immunodeficiency (SCID): JAK3 (Known Mutation)

Test Includes

All coding nucleotides of the specified gene(s), plus at least two and typically 20 nucleotides flanking each coding region.

Special Instructions

This option is available when the mutation is known and can be documented by the ordering physician. If the mutation cannot be documented, please order test 252466. Test orders must include an attestation that the provider has the patient's informed consent for genetic testing. See sample physician office consent form: Consent for Genetic Testing. In the case of family tests (ie, known mutations), please submit the result report of the first patient tested in the family (the index case), if not performed at a LabCorp facility. Other family members are subsequently tested for the specific mutation found in the first patient tested.

Expected Turnaround Time

21 - 28 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Test Details

Methodology

DNA sequencing

Sex Determination (SRY), DNA Analysis

Synonyms

Sex Reversal
SRY Determination
Swyer Syndrome

Expected Turnaround Time

8 - 14 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Specimen Requirements

Specimen

Whole blood, amniotic fluid or LabCorp buccal swab kit (Buccal swab collection kit contains instructions for use of a buccal swab.) or chorionic villus sample (CVS)

Volume

7 mL whole blood, 10 mL amniotic fluid, LabCorp buccal swab kit, or 20 mg CVS

Minimum Volume

3 mL whole blood, 5 mL amniotic fluid, two buccal swabs, or 10 mg CVS

Container

Lavender-top (EDTA) tube, sterile plastic conical tube, or LabCorp buccal swab kit

Storage Instructions

Maintain specimen at room temperature.

Causes for Rejection

Frozen specimen; hemolysis; quantity not sufficient for analysis; improper container; one buccal swab; wet buccal swab

Test Details

Use

Resolution of unexplained sex reversal or infertility through detection of the SRY gene; can help rule out mosaicism for 46,XY cells in Turner syndrome patients

Limitations

Results of this test are for investigational purposes only. The performance characteristics of this assay have been determined by LabCorp. The result should not be used as a diagnostic procedure without confirmation of the diagnosis by another medically established diagnostic product or procedure.

Methodology

Polymerase chain reaction (PCR) and gel electrophoresis

Additional Information

The SRY gene (OMIM 480000) is the testis-determining factor, the primary switch responsible for initiating testis development. The presence of a functional SRY gene is essential for normal gonadal development in males. In rare cases, mutations within the SRY gene can cause sex reversal and gonadal dysgenesis in XY females. Individuals with a male karyotype (46,XY) who lack the SRY gene will develop as females, and be infertile. Individuals with a female karyotype (46,XX) who carry the SRY gene will develop as infertile males.

Sex Hormone-binding Globulin

Synonyms

Testosterone-binding Globulin

Special Instructions

This test may exhibit interference when sample is collected from a person who is consuming a supplement with a high dose of biotin (also termed as vitamin B7 or B8, vitamin H, or coenzyme R). It is recommended to ask all patients who may be indicated for this test about biotin supplementation. Patients should be cautioned to stop biotin consumption at least 72 hours prior to the collection of a sample.

Expected Turnaround Time

Within 1 day

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Specimen Requirements

Specimen

Serum

Volume

0.8 mL

Minimum Volume

0.3 mL (Note: This volume does not allow for repeat testing.)

Container

Red-top tube or gel-barrier tube

Collection

If a red-top tube is used, transfer separated serum to a plastic transport tube.

Storage Instructions

Room temperature

Stability Requirements

Temperature	Period
Room temperature	14 days
Refrigerated	14 days
Frozen	14 days
Freeze/thaw cycles	Stable x3

Causes for Rejection

Citrate plasma specimen; EDTA plasma specimen; improper labeling

Test Details

Use

Levels of SHBG are under the positive control of estrogens and thyroid hormones, and are suppressed by androgens. These influences dynamically control the liver synthesis of this carrier protein. Decreased levels of SHBG are frequently seen in hirsutism, virilization, obese postmenopausal women, and in women with diffuse hair loss. Increased levels may be present in cases of hyperthyroidism, testicular feminization, cirrhosis, male hypogonadism, pregnancy, women using oral contraceptives, and prepubertal children.

Limitations

As with all tests containing monoclonal mouse antibodies, erroneous findings may be obtained from samples taken from patients who have been treated with monoclonal mouse antibodies or who have received them for diagnostic purposes.¹ In rare cases, interference due to extremely high titers of antibodies to streptavidin and ruthenium can occur.¹ The test contains additives that minimize these effects.

Methodology

Electrochemiluminescence immunoassay (ECLIA)

Reference Interval

• Male: − 20-49 years: 16.5−55.9 nmol/L − >49 years: 19.3−76.4 nmol/L • Female: − 20-49 years: 24.6−122.0 nmol/L − >49 years: 17.3−125.0 nmol/L

Additional Information

Sex hormone-binding globulin (SHBG) is the blood transport protein for testosterone and estradiol. It is a large glycoprotein with a molecular weight of about 95 kD and exists as a homodimer composed of two identical subunits. Each subunit contains two disulfide bridges.² Planar C¹⁸ and C¹⁹ steroids with a 17α-hydroxyl group bind particularly well,^3,4 whereas C¹⁹ 17-ketosteroids, such as dehydroepiandrosterone (DHEA) and androstenedione, do not bind so easily. SHBG has a high binding affinity to dihydrotestosterone (DHT), medium affinity to testosterone and estradiol, and only a low affinity to estrone, DHEA, androstenedione, and estriol. SHBG binds reversibly to sexual steroids. Albumin, which exists in far higher concentrations than SHBG, also binds to sexual steroids−although with a clearly lower binding affinity (eg, about 100 times lower for testosterone). SHBG has a half-life of about seven days and is produced mainly by the liver. Its synthesis and secretion are regulated by estrogen.^5,6 SHBG serum concentrations depend on the extent, duration, and the kind of estrogen applied, and how regulation takes place. Androgens and gestagens with androgenic residual action have the opposite effect. In serum, SHBG mainly takes over the transportation of steroids and the reduction/regulation of the effect of androgen.^7,8 Decreased SHBG serum levels are associated with conditions in which elevated androgen levels are present or in which the effect of androgen on its target organs is excessive. This explains the gender-related differences seen between men and women, especially during puberty. Measurement of SHBG can be an important indicator of an excessive/chronic androgenic action where androgen levels are normal, but where clinical symptoms would seem to indicate androgen in excess. SHBG is a useful supplementary parameter in the determination of androgen where a relatively high concentration of free androgen (eg, testosterone) is suspected.⁹ By calculating the free androgen index (FAI), also called free testosterone index (FTI), from the ratio of total testosterone (TT) to SHBG [% FAI or FTI = (TT / SHBG) x 100], it is possible to calculate the approximate amount of free testosterone (FTc), as there is a direct correlation between FAI and FT. Only free testosterone is biologically active, and it best indicates the clinical situation of the patient. Free testosterone is also referred to as non-SHBG-bound testosterone and can be obtained by precipitation of the SHBG-bound-testosterone with ammonium sulfate, and by equilibrium dialysis.^10,11 Elevated SHBG levels can be seen in elderly men, and are often found in patients with hyperthyroidism and cirrhosis of the liver. SHBG levels also increase when oral contraceptives or antiepileptic drugs are taken. Pregnant women have markedly higher SHBG serum concentrations due to their increased estrogen production. Decreased SHBG concentrations are often seen with hypothyroidism, polycystic ovarian syndrome (PCOS), obesity, hirsutism, elevated androgen levels, alopecia, and acromegaly.

SHOX, DHPLC (Endocrine Sciences)

Synonyms

Short Stature Homeobox

Expected Turnaround Time

18 - 30 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Specimen Requirements

Specimen

Whole blood

Volume

3 mL

Minimum Volume

1 mL

Container

Lavender-top (EDTA) tube or yellow-top (ACD) tube

Storage Instructions

Maintain specimen at room temperature.

Stability Requirements

Temperature	Period
Room temperature	28 days
Refrigerated	28 days

Test Details

Use

Identifies mutations causing short stature related to SHOX deficiency. SHOX deficiency is an indication for somatotropin (Humatrope®).

Methodology

Denaturing high-pressure liquid chromatography (DHPLC)

Sickle Cell Anemia Mutation Analysis, Fetal

Synonyms

Sickle Cell Anemia, Prenatal

Special Instructions

This test is for fetal/prenatal cases and parental controls. It is not intended for routine sickle cell screening. Please call 800-345-4363 with any questions regarding selection of tests.

Expected Turnaround Time

8 - 14 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Specimen Requirements

Specimen

Amniotic fluid or chorionic villus sample (CVS)

Volume

12 mL amniotic fluid or 20 mg CVS and 5 mL blood per parental sample

Minimum Volume

10 mL amniotic fluid or 10 mg CVS and 2 mL blood per parental sample.

Container

Sterile plastic conical tube or two confluent T-25 flasks and lavender-top (EDTA) tube

Collection

Do not use urine container, syringes, or tubes with rubber-stoppers. Rubber is toxic to amniocytes.

Storage Instructions

Maintain specimen at room temperature.

Causes for Rejection

Specimen frozen; specimen found not to be amniotic fluid; quantity not sufficient for analysis; improper container

Test Details

Use

DNA analysis to detect mutations known to cause sickle cell anemia

Limitations

False-positive and false-negative results may occur for reasons that include genetic variants, blood transfusions, bone marrow transplantation, erroneous representation of family relationships, or contamination of a fetal sample with maternal cells.

Methodology

DNA is isolated and the targeted region of the HBB gene amplified by the polymerase chain reaction (PCR). HbS or HbC mutations are identified by direct DNA sequencing using capillary gel electrophoresis and fluorescence detetion. False positive or negative results may occur for reasons that include genetic variants, blood transfusions, bone marrow transplantation, erroneous representation of family relationships or contamination of a fetal sample with maternal cells.

Sirolimus, Whole Blood

Synonyms

Rapamune®

Expected Turnaround Time

2 - 4 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Specimen Requirements

Specimen

Whole blood

Volume

3 mL

Minimum Volume

1.1 mL

Container

Lavender-top (EDTA) tube

Collection

Trough: 30 minutes to one hour before the next oral dose

Storage Instructions

Room temperature

Stability Requirements

Temperature	Period
Room temperature	14 days
Refrigerated	14 days
Frozen	14 days
Freeze/thaw cycles	Stable x3

Causes for Rejection

Clotted specimen

Test Details

Use

Monitor immunosuppressive therapy following organ transplant

Limitations

This test was developed and its performance characteristics determined by LabCorp. It has not been cleared or approved by the Food and Drug Administration.

Methodology

Liquid chromatography/tandem mass spectrometry (LC/MS-MS)

Reference Interval

3.0−20.0 ng/mL

Additional Information

Sirolimus may be administered in conjunction with cyclosporine (CsA) and corticosteroids to reduce or prevent host graft rejection. Using this therapy, peak concentrations are achieved in one to two hours. The mean terminal elimination half-life is 62 hours.¹ Drug-drug interactions, including CsA, may alter the pharmacokinetics of sirolimus, making therapeutic drug monitoring appropriate.

Skin Biopsy

Synonyms

H and E Sections
Punch Biopsy
Skin Lesion

Test Includes

Microscopic examination of tissue sections

Special Instructions

For histopathology, order .

Specimen Requirements

Specimen

Skin punch biopsy

Volume

Complete biopsy

Container

Jar or test tube with 10% formalin

Collection

Place skin biopsy immediately in formalin in container provided. Label with patient's name, biopsy site, and date.

Storage Instructions

Maintain specimen at room temperature.

Causes for Rejection

Improper labeling; specimen not received in formalin

Test Details

Use

Document specimen removed by surgery

Sodium

Expected Turnaround Time

Within 1 day

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Specimen Requirements

Specimen

Serum (preferred) or plasma

Volume

1 mL

Minimum Volume

0.5 mL

Container

Red-top tube, gel-barrier tube, or green-top (lithium heparin) tube

Collection

Separate serum or plasma from cells within 45 minutes of collection. Label specimen as serum.

Storage Instructions

Maintain specimen at room temperature.

Stability Requirements

Temperature	Period
Room temperature	14 days
Refrigerated	14 days
Frozen	14 days
Freeze/thaw cycles	Stable x3

Causes for Rejection

Gross hemolysis; improper labeling

Test Details

Use

Electrolyte, acid-base balance; water balance; water intoxication; diagnose dehydration. Hypernatremia occurs in dehydration. For instance, nasogastric protein feeding with insufficient fluids may cause hypernatremia. Hypernatremia without obvious cause may relate to Cushing syndrome, central or nephrogenic diabetes insipidus with insufficient fluids, primary aldosteronism, and other diseases. Severe hypernatremia may be associated with volume contraction, lactic acidosis, azotemia, weight loss, and increased hematocrit as evidence of dehydration. The corrected serum sodium is often high in nonketotic hyperosmolar coma. (A corrected Na⁺ is calculated by increasing Na⁺ by 1.3−1.6 mmol/L for each 100 mg/dL increment in serum or plasma glucose). 100 mg equals 5.56 mmol/L. The corrected serum sodium level calculated in nonketotic hyperosmolar coma: apparent mild hyponatremia with very high glucose may actually mean (corrected) hypernatremia.¹ Hyponatremia occurs with nephrotic syndrome, cachexia, hypoproteinemia, intravenous glucose infusion, in congestive heart failure, and other clinical entities. Serum sodium is a predictor of cardiovascular mortality in patients in severe congestive heart failure.² Hyponatremia without congestive failure or dehydration may occur with hypothyroidism, the syndrome of inappropriate secretion of antidiuretic hormone (SIADH), renal failure, or renal sodium loss. The differential diagnosis of hyponatremia includes Addison disease, hypopituitarism, liver disease including cirrhosis, hypertriglyceridemia, and psychogenic polydipsia. Diuretics and other drugs may cause hyponatremia. Sodium decreasing to levels <115 mmol/L can lead to significant neurological dysfunction with cerebral edema and increased intracranial pressure. The differential diagnosis of hyponatremia includes determination of urine sodium and osmolality and serum urea nitrogen (BUN). BUN is often decreased in SIADH.

Methodology

Ion-selective electrode (ISE); flame photometer

Reference Interval

134−144 mmol/L

Additional Information

The ratio of serum sodium:osmolality is normally 0.43−0.50; a decreased ratio is found in uremia and other states in which there are increased substances with osmotic activity. See Urea Nitrogen [001040], regarding hyponatremia with sodium <128 mmol/L, hypo-osmolality, low BUN and the syndrome of inappropriate secretion of antidiuretic hormone. A number of situations result in “pseudohyponatremia.” In these circumstances treatment may be undesirable. With pseudohyponatremia serum sodium is decreased but the serum is not hypotonic (serum osmolality is normal or even increased). This may occur as the result of other molecules replacing water in relation to sodium. The water content is effectively lowered − sodium is “diluted.” In severe hypertriglyceridemia or paraprotein-related marked increase in protein, the concentration of sodium in relation to water is normal but the analytic result is determined as mmol/L of serum. Osmolality in this situation is determined as amount of particles per kg of water and will be normal. It has been shown that analyses by sodium electrode of the direct potentiometric type (requires no dilution) are not artifactually low in patients with hyperlipidemia.³ If large amounts of solute such as glucose or mannitol are present, movement of intracellular water into the extracellular space may produce dilutional hyponatremia. In this case sodium concentration in relation to water is actually low. “Osmolal gap” however exists between measured and calculated serum osmolality. Other substances capable of increasing serum osmolality (eg, ethanol) may also cause increase in the osmolal gap. Yet another cause of pseudohyponatremia is increased serum viscosity due to increased globulin proteins, occurring particularly in Waldenström macroglobulinemia. The sodium analyzer may aspirate too little sample when viscosity is so increased, leading to a factitious low sodium concentration. See discussion of “pseudohyponatremia” by Epstein and Osler.⁴ Hyponatremia may manifest lethal neurological complications (water intoxication with brain edema). Rapid correction of hyponatremia has been described⁵ but has also been implicated as a cause of demyelination.⁶ Hypernatremia may complicate some cases of lactulose-treated portal-systemic encephalopathy.⁷ Drug effects are summarized.⁸

Sodium, 24-Hour Urine

Special Instructions

The test request form must state date and time collection started, date and time collection finished, and 24-hour urine volume.

Expected Turnaround Time

Within 1 day

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Related Information

Urine Specimens

Specimen Requirements

Specimen

Urine (24-hour)

Volume

10 mL aliquot

Minimum Volume

1 mL aliquot

Container

Plastic urine container without preservative

Collection

Instruct the patient to void at 8 AM and discard the specimen. Then collect all urine including the final specimen voided at the end of the 24-hour collection period (ie, 8 AM the next morning). Screw the lid on securely. Container must be labeled with patient's full name, date and time collection started, and date and time collection finished.

Storage Instructions

Room temperature

Stability Requirements

Temperature	Period
Room temperature	14 days
Refrigerated	14 days
Frozen	14 days
Freeze/thaw cycles	Stable x3

Causes for Rejection

Improper labeling

Test Details

Use

Work up volume depletion, acute renal failure, acute oliguria, and differential diagnosis of hyponatremia.¹ Division of hyponatremia into hypervolemia or not, edema or not, and urinary Na⁺ less than or greater than 10 mmol/L provides a classification of hyponatremia.² History of diuretics, other drug intake, setting of osmotic diuresis or not, serum or plasma electrolytes and other factors are needed.

Methodology

Ion-selective electrode (ISE); flame photometer

Reference Interval

Age	Male (mmol/24 hr)	Female (mmol/24 hr)
0 to 5 y	Not established	Not established
6 to 12 y	Not established	33-185
13 to 17 y	30-250	30-250
18 to 80 y	58-337	39-258
>80 y	23-207	23-207

Additional Information

In cases of hyponatremia, urine sodium <10 mmol/L may indicate extrarenal depletion: dehydration (gastrointestinal or sweat loss), congestive heart failure, liver disease or nephrotic syndromes. Urine sodium >10 mmol/L may indicate diuretics, emesis, intrinsic renal diseases, Addison disease, hypothyroidism, or syndrome of inappropriate antidiuretic hormone (SIADH).² In hypothyroidism and in SIADH, Na⁺ and Cl^- may be >40 mmol/L.³ (Depending on intake, such results also can be found in normal individuals.) In SIADH, urinary sodium is usually >20 mmol/L. Inappropriate secretion of antidiuretic hormone (SIADH) was found in 7% of 250 patients with small cell lung cancer.⁴ Such patients have hyponatremia, often severe, with hypo-osmolar serum, high urinary sodium excretion with urine osmolality greater than that of serum. Acute and subacute diseases of the CNS, TB and other chronic pulmonary diseases may also cause SIADH. SIADH may also be caused by acute intermittent porphyria, LE, occasional malignant neoplasms other than small cell carcinoma of lung, and a number of drugs.⁵ The classification as presented here is overly abbreviated for clinical application. Pitfalls exist (eg, increase of Na⁺ necessary to balance excretion of penicillin).³ Urine Na⁺ >40 mmol/L in oliguria suggests acute tubular necrosis.^3,6 (However, spot urine sodiums without other data have been criticized for their applicability to this diagnosis.) Low Na⁺ excretion may be found with early obstructive uropathy and with the oliguria of acute glomerulonephritis³ and in some patients with x-ray contrast acute renal failure. Silver et al recommend measurement of urinary Na⁺ excretion in patients with nephrolithiasis and hypercalciuria.⁷ It is important to know the urinary sodium level in patients with unexplained hyperchloremic metabolic acidosis when the diagnosis of distal renal tubular acidosis is being considered.⁸

Soluble Liver Antigen (SLA) IgG Antibody

Synonyms

SLA, IgG Antibody

Expected Turnaround Time

4 - 6 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Specimen Requirements

Specimen

Serum

Volume

0.6 mL

Minimum Volume

0.3 mL (Note: This volume does not allow for repeat testing.)

Container

Red-top tube or gel-barrier tube

Collection

If a red-top tube is used, transfer separated serum to a plastic transport tube.

Storage Instructions

Refrigerate

Causes for Rejection

Nonserum specimen received; specimen in azide or other preservative; microbially-contaminated specimen; heat-treated specimen; gross lipemia or hemolysis

Test Details

Use

Aid in the diagnosis of autoimmune hepatitis (AIH)^1-4

Limitations

A negative SLA IgG does not rule out autoimmune hepatitis.

Methodology

Enzyme immunoassay (EIA)

Reference Interval

• Negative: 0.0−20.0 units • Equivocal: 20.1−24.9 units • Positive: >24.9 units

Additional Information

Autoimmune hepatitis (AIH) is a chronic, progressive, heterogeneous inflammatory liver disease of unknown etiology.⁴ Diagnosis is often difficult since there is no single diagnostic test for AIH and presenting symptoms can be quite varied. Diagnosis includes evaluation of clinical laboratory and histological findings as well as the exclusion of other causes of chronic hepatitis. Diagnosis is particularly difficult with patients classified with cryptogenic hepatitis, described as having an undefined chronic hepatitis without antibodies to viral or the conventional profile of autoimmune markers. Early diagnosis of AIH and immunosuppressive treatment are essential to help prevent severe liver damage. AIH patients are generally divided into two groups based on the presence of specific autoantibodies.^2,4 AIH type 1 (also referred to as classic, active chronic, lupoid, plasma cell, or autoimmune chronic active hepatitis) is the more common type of AIH. AIH-1 is characterized by antinuclear, antismooth muscle (directed against both antiactin and nonactin components), and perinuclear and antineutrophil cytoplasmic antibodies. Liver/kidney microsome antibodies and antiliver cytosol antigen (LC-1) characterize AIH type 2. Autoantibodies against soluble liver antigen (anti-SLA) show a high specificity (approximately 99%) for AIH;^1,2 however, they are detectable in only 10% to 30% of patients with AIH.³ SLA is a 50 kilodalton cytosolic protein that is thought to be involved in the selenocysteine pathway.^2,4 Anti-SLA and the independently described anti-LP are identical.³ The findings of anti-SLA has been associated with an increased prevalence of the HLA-DR3 genotype and a decreased prevalence of the HLA-DR4 genotype.^2,3 Anti-SLA positive patients have a higher rate of relapse after corticosteroid than seronegative patients.³ Recent studies have suggested that patients with anti-SLA/LP have a more severe course of autoimmune hepatitis, although the exact function and role of this autoantibody remain unclear.³

Soluble Transferrin Receptor

Synonyms

sTfR
Transferrin Receptor

Expected Turnaround Time

2 - 3 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Specimen Requirements

Specimen

Serum or plasma

Volume

1 mL

Minimum Volume

0.2 mL (Note: This volume does not allow for repeat testing.)

Container

Red-top tube, green-top (heparin) tube, or lavender-top (EDTA) tube

Collection

Separate serum or plasma from cells and transfer to a plastic transport tube.

Storage Instructions

Refrigerate.

Causes for Rejection

Gross hemolysis; use of yellow-top tube

Test Details

Use

Measurement of sTfR is used to diagnose iron deficiency in individuals with chronic disease (inflammatory diseases, infections, malignancies), many of whom are anemic.

Methodology

Immunochemiluminometric assay (ICMA)

Reference Interval

12.2−27.3 nmol/L

Additional Information

Anemia of chronic disease and iron deficiency anemia, the most common forms of anemia, are differentiated primarily by estimates of iron status. Standard measures of iron status, such as ferritin, total iron-binding capacity, and serum iron are directly affected by chronic disease. In contrast, soluble transferrin receptor (sTfR) is elevated in iron deficiency but is not appreciably affected by chronic disease. sTfR is elevated in subjects with hyperplastic erythropoiesis (eg, hemolytic anemia, beta-thalassemia, polycythemia, etc) and depressed in subjects with hypoplastic erythropoiesis (eg, chronic renal failure, aplastic anemia, or post-transplant anemia). Transferrin receptor (TfR) is the major mediator of iron uptake by cells. TfR is a transmembrane, disulfide-linked dimer of two identical subunits that binds and internalizes diferric transferrin, thereby delivering iron to the cell cytosol. When a cell needs iron, TfR expression is increased to facilitate iron uptake. Since the major use of iron is for hemoglobin synthesis, about 80% of total TfR is on erythroid progenitor cells. Soluble transferrin receptor arises from proteolysis of the intact protein on the cell surface, leading to monomers that can be measured in plasma and serum. Thus, the concentration of sTfR in plasma or serum is an indirect measure of total TfR. The serum level of sTfR reflects either the cellular need for iron or the rate of erythropoiesis. The concentration of sTfR in plasma or serum is elevated in iron deficiency. The concentration of sTfR in plasma or serum is correlated with erythron transferrin uptake, a ferrokinetic measure of erythropoietic activity.

Solvent Inhalants Profile, Urine Metabolites

Test Includes

Trichloroacetic acid; total trichloroethanol; hippuric acid; mandelic acid; methylhippuric acid; phenylglyoxylic acid; o-cresol, phenol

Expected Turnaround Time

14 - 21 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Specimen Requirements

Specimen

Urine (random)

Volume

10 mL

Minimum Volume

2 mL

Container

Plastic urine container without preservative

Collection

Container should be filled to prevent loss of volatile compound into headspace.

Storage Instructions

Refrigerate; specimen may also be frozen.

Causes for Rejection

Urine from preservative tube

Test Details

Use

Evaluate exposure to inhalants

Methodology

Gas chromatography/flame Ionization detection (GC/FID); headspace gas chromatography/electron capture detection (GC/EC)

Spinal Muscular Atrophy (SMA) Carrier Testing

Synonyms

SMN1 Copy-number Analysis
Arthron-ryposis Multiplex Congenita (Prenatal SMA)
Congenital Axonal Neurotherapy
Dubowitz Disease (SMA Type II)
Kugelberg-Welander Disease (SMA Type III)
Werdnig-Hoffmann Disease (SMA Type I)

Special Instructions

For prenatal testing, please refer to test code 452140, Prenatal Spinal Muscular Atrophy (SMA) Testing.

Expected Turnaround Time

7 - 13 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Related Information

Prenatal Spinal Muscular Atrophy (SMA) Testing

Specimen Requirements

Specimen

Whole blood

Volume

Adults: 10 mL whole blood; 20 mL whole blood if ordering multiple tests

Container

Whole blood: Yellow-top (ACD-A) tube (preferred) or lavender-top (EDTA) tube; yellow-top (ACD-B) tube is not acceptable

Storage Instructions

Maintain specimen at room temperature.

Causes for Rejection

Frozen or hemolyzed specimen; quantity not sufficient for analysis; blood specimens more than four days post draw

Test Details

Use

Carrier testing for individuals in the general population, or individuals with a family history of SMA, or couples who are planning a pregnancy or who are already pregnant. Pediatric or adult diagnostic testing when a diagnosis of SMA is suspected. Test 452140, Prenatal Spinal Muscular Atrophy (SMA) Testing, should be used for prenatal diagnosis for at-risk pregnancies, when both parents are carriers or when severe joint contractures are found on fetal ultrasound.

Limitations

This copy number analysis does not detect individuals who are carriers of SMA as a result of either two (or very rarely three) copies of the SMN1 gene on one chromosome and the absence of the SMN1 gene on the other chromosome; or germline mosaicism; or small intragenic mutations within the SMN1 gene; or mutations in genes other than SMN1. False-positive results or false-negative results may occur for reasons that include genetic variants, blood transfusions, bone marrow transplantation, erroneous representation of family relationships, or contamination of a fetal sample with maternal cells.

Methodology

After DNA is isolated, exon 7 of the SMN1 gene and internal standard reference genes are amplified by real-time polymerase chain reaction (PCR). A mathematical algorithm calculates SMN1 copy numbers of 0, 1, 2, or 3 with statistical confidence. To rule out the presence of sequence variants that could interfere with analysis and interpretation, sequence analysis of primer and probe binding sites is performed for samples with one copy of SMN1. Reflex testing to SMN2 copy number analysis is performed for specimens with 0 copies of SMN1.

Additional Information

Spinal muscular atrophy (SMA) is an autosomal recessive disease caused by deletions or, less often, point mutation(s) in the SMN1 gene, leading to a reduction in the amount of survival motor neuron (SMN) protein. SMA is characterized by the progressive degeneration of the lower motor neurons, leading to muscle weakness and, in the most common type, respiratory failure by age two. Muscles responsible for crawling, walking, swallowing, and head and neck control are the most severely affected. The SMN2 gene is adjacent to SMN1 and encodes low levels of the SMN protein. An increase in SMN2 copy number (3+) may reduce disease severity among affected individuals.

Stemphylium herbarum

Expected Turnaround Time

2 - 4 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Related Information

Individual Allergens

Specimen Requirements

Specimen

Serum

Volume

0.2 mL

Container

Red-top tube or gel-barrier tube

Storage Instructions

Room temperature

Stability Requirements

Temperature	Period
Room temperature	14 days
Refrigerated	14 days
Frozen	3 months
Freeze/thaw cycles	Stable x3

Test Details

Methodology

Thermo Fisher ImmunoCAP®

Stool Culture

Synonyms

Culture, Stool, Comprehensive
Enteric Pathogens Culture, Routine
Feces Culture, Routine
Routine Culture, Stool

Test Includes

Culture; isolation and identification (at an additional charge) of Salmonella, Shigella, and Campylobacter, and detection of enterohemorrhagic E coli (EHEC) Shiga toxin by EIA. If culture results warrant, susceptibility testing (additional charges/CPT code[s] may apply) may be performed. CPT coding for microbiology and virology procedures often cannot be determined before the culture is performed. Requests with only a written order and no test number indicated will be processed according to Default Testing for Routine Microbiology.

Special Instructions

Specify specific pathogen if not Salmonella, Shigella, Campylobacter, or enterohemorrhagic E coli (EHEC). Check expiration date of transport; do not use expired devices. Fecal specimens for different tests often need different transport containers and different transport conditions (eg, frozen, raw stool). Specimens should be portioned out to separate devices of each type for each test requested before sending to the laboratory. Stool for bacterial culture and enterohemorrhagic E coli Shiga toxin by EIA should be submitted in the C&S transport vial. Only a thumbnail-size portion of stool, about 1 g or 1 mL, should be added to the vial. Overfilling the vial will reduce recovery of stool pathogens. Specimens from sources, such as genital, stool, urine, and upper and lower respiratory specimens, cannot be cultured under the aerobic bacterial culture test number. If specimens are incorrectly submitted with an order for aerobic bacterial culture, the laboratory will process the specimen for the test based on the source listed on the request form. The client will not be telephoned to approve this change, but the change will be indicated on the report.

Expected Turnaround Time

3 - 5 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Related Information

Specimen Requirements

Specimen

Stool or rectal swab

Volume

1 g, 1 mL, or one swab in stool C&S transport vial (usual bacterial swab transport is not acceptable although the swab may be used)

Container

Stool culture transport vial is required; diapers are not acceptable. Culture collection swab may be used to collect rectal swabs or a swab of fecal material, then swab should be placed in stool culture transport vial (Para-Pak® C&S orange).

Collection

A single stool specimen cannot be used to rule out bacteria as a cause of diarrhea. It is recommended that two or three stool specimens, collected on separate days, be submitted to increase the probability of isolating a bacterial pathogen. Hospitalized patients who develop diarrhea while hospitalized and more than 72 hours after admission should be tested for Clostridium difficile by detection of either toxin A and/or toxin B. Studies have shown that patients who did not have gastroenteritis or other GI symptoms on admission are unlikely to have diarrheal illness due to Salmonella, Shigella, Campylobacter, or enterohemorrhagic E coli. Stool: Specimen should be collected in sterile bedpan, not contaminated with urine, residual soap, or disinfectants. Those portions of stool that contain pus, blood, or mucus should be transferred to a sterile specimen container. Rectal swab: Pass swab beyond anal sphincter, carefully rotate, and withdraw. Swabbing of lesions of rectal wall or sigmoid colon during proctoscopy or sigmoidoscopy is preferred. Duodenal or sigmoid aspirate: Specimen should be collected by a physician trained in this procedure. Stool specimen can be divided for other types of cultures by the laboratory. Miscellaneous tests and ova and parasites tests should be split into appropriate containers and transport devices prior to shipping to the laboratory.

Storage Instructions

Maintain specimen at room temperature.

Causes for Rejection

Specimen received in grossly leaking transport container; diapers; dry specimen; specimen submitted in fixative or additive; specimen received in expired transport media or incorrect transport device; inappropriate specimen transport conditions (not in a C&S vial or in an overfilled C&S vial); specimen received after prolonged delay in transport (usually more than 72 hours); specimen stored or transported frozen; wooden shaft swab in transport device; unlabeled specimen or name discrepancy between specimen and request label

Test Details

Use

Detect bacterial pathogenic organisms in the stool; diagnose typhoid fever, enteric fever, bacillary dysentery, Salmonella infection. Indications for stool culture include:¹ • Bloody diarrhea • Fever • Tenesmus • Severe or persistent symptoms • Recent travel to a third world country • Known exposure to a bacterial agent • Presence of fecal leukocytes

Limitations

Yersinia sp and Vibrio parahaemolyticus will not be isolated unless specifically requested; these will each be done with an additional charge. These organisms are fastidious and have very specific requirements for growth.

Methodology

Aerobic culture on selective media; detection of EHEC Shiga-like toxins by enzyme immunoassay (EIA)

Contraindications

A rectal swab culture is not as effective as a stool culture for detection of the carrier state.

Additional Information

In enteric fever caused by Salmonella typhi, S choleraesuis, or S enteritidis, blood culture may be positive before stool cultures, and blood cultures are indicated early; urine cultures may also be helpful. Diarrhea is common in patients with the acquired immunodeficiency syndrome (AIDS). It is frequently caused by the classic bacterial pathogens as well as unusual opportunistic bacterial pathogens and parasitic infestation. (Giardia, Cryptosporidium, and Entamoeba histolytica frequently reported.) Cryptosporidium, Isospora, and Pneumocystis can occur with AIDS. Rectal swabs are useful for the diagnosis of Neisseria gonorrhoeae and Chlamydia infections. AIDS patients are also subject to cytomegalovirus, Salmonella, Campylobacter, Shigella, C difficile, herpes, and Treponema pallidum gastrointestinal tract involvement.

Diarrhea Syndromes Classified by Predominant Features
Syndrome (Anatomic Site)	Features	Characteristic Etiologies
Gastroenteritis (stomach)	Vomiting	Rotavirus Norwalk virus Staphylococcal food poisoning Bacillus cereus food poisoning
Enteritis (small bowel)	Watery diarrhea Large-volume stools, few in number	Enterotoxigenic Escherichia coli Vibrio cholerae Any enteric microbe Inflammatory bowel disease
Dysentery, colitis (colon)	Small-volume stools containing blood and/or mucus and many leukocytes	Shigella Campylobacter Salmonella Invasive E coli Plesiomonas shigelloides Aeromonas hydrophila Vibrio parahaemolyticus Clostridium difficile Entamoeba histolytica Inflammatory bowel disease

In acute or subacute diarrhea, three common syndromes are recognized: gastroenteritis, enteritis, and colitis (dysenteric syndrome). With colitis, patients have fecal urgency and tenesmus. Stools are frequently small in volume and contain blood, mucus, and leukocytes. External hemorrhoids are common and painful. Diarrhea of small bowel origin is indicated by the passage of few large volume stools. This is due to accumulation of fluid in the large bowel before passage. Leukocytes indicate colonic inflammation rather than a specific pathogen. Bacterial diarrhea may be present in the absence of fecal leukocytes and fecal leukocytes may be present in the absence of bacterial or parasitic agents (ie, idiopathic inflammatory bowel disease).² See table. Although most bacterial diarrhea is transient (1 to 30 days) cases of persistent symptoms (10 months) have been reported. The etiologic agent in the reported case was Shigella flexneri diagnosed by culture of rectal swab.³ In infants younger than one year of age, a history of blood in the stool, more than 10 stools in 24 hours, and temperature greater than 39°C have a high probability of having bacterial diarrhea.^4,5 Diarrhea is also a common side effect of long-term antibiotic treatment. Although often associated with Clostridium difficile, other bacteria and yeasts have been implicated.⁶

Substance Abuse Monitoring and Rehabilitation Profile I, Oral Fluid (Screen and Confirmation) (LabCorp MedWatch®)

Test Includes

Amphetamine; cocaine and metabolites; opiates; oxycodone/oxymorphone; phencyclidine (PCP); tetrahydrocannabinol (THC); reflex to confirmation. Opiate confirmation of a positive screen includes codeine, morphine, and 6-acetylmorphine (6-AM).

Expected Turnaround Time

4 - 6 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Specimen Requirements

Specimen

Saliva, oral fluid

Volume

1 mL

Container

Quantisal™ oral fluid collection device. Contact the lab for collection kit.

Storage Instructions

Maintain specimen at room temperature for transport to laboratory; refrigerate if transport is delayed.

Test Details

Use

Detect the presence of illicit drugs

Methodology

Initial test: Immunoassay (IA); Confirmation: mass spectrometry (MS)

Substance Abuse Monitoring and Rehabilitation Profile II, Oral Fluid (Screen Only) (LabCorp MedWatch®)

Synonyms

Immunoassay ELISA 10
LabCorp MedWatch®: Recovery

Expected Turnaround Time

1 - 5 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Specimen Requirements

Specimen

Saliva, oral fluid

Volume

1 mL

Container

Quantisal™ oral fluid collection device. Contact lab for collection kit.

Storage Instructions

Maintain specimen at room temperature for transport to laboratory; refrigerate if transport is delayed.

Test Details

Methodology

Immunoassay (IA)

Substance Abuse Monitoring and Rehabilitation Profile, Urine (Screen With Confirmation)

Test Includes

Amphetamines; Barbiturate; Benzodiazepines; Cannabinoid; Cocaine (Metab.); Opiates; 6-Acetylmorphine; Oxycodone/Oxymorphone; EDDP; Adulteration (Dilution)

Special Instructions

This panel is designed for substance abuse treatment programs. It is not intended for workplace testing and does not comply with regulatory workplace testing programs. Note: Test set-up allows for preliminary results to print.

Expected Turnaround Time

4 - 6 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Specimen Requirements

Specimen

Urine

Volume

50 mL

Container

Urine container

Storage Instructions

Maintain specimen at room temperature. Stability: If arrival will extend beyond 7 days, then refrigerate.

Test Details

Methodology

Initial testing by immunoassay; confirmation of positives by mass spectrometry

Sufentanil, Serum or Plasma

Synonyms

Sufenta®

Expected Turnaround Time

5 - 7 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Specimen Requirements

Specimen

Serum or plasma

Volume

2 mL

Container

Red-top tube or green-top (heparin) tube. Gel-barrier tubes are not recommended.

Collection

Serum or plasma should be separated from cells within two hours of venipuncture. Submit serum or plasma in a plastic transport tube.

Storage Instructions

Submission/transport (<3 days): Room temperature. For storage beyond three days, specimen should be refrigerated or frozen. Specimen is stable for five days at room temperature, for five days refrigerated, and for three weeks frozen.

Patient Preparation

Trough levels are most reproducible.

Causes for Rejection

Gel-barrier tubes

Test Details

Use

Therapeutic drug management

Methodology

Liquid chromatography/tandem mass spectrometry (LC/MS-MS)

Reference Interval

Expected analgesic concentrations in opiate-naïve patients: up to 2.5 ng/mL

Sulfonylurea Analysis, Serum or Plasma

Test Includes

Acetohexamide; chlorpropamide; glimepiride; glipizide; glyburide; nateglinide; repaglinide; tolazamide; tolbutamide

Expected Turnaround Time

10 - 14 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Specimen Requirements

Specimen

Serum or plasma

Volume

2 mL

Minimum Volume

1 mL

Container

Red-top tubeor green-top (heparin) tube. Gel-barrier tubes are not recommended.

Collection

Serum or plasma should be separated from cells within two hours of venipuncture. Submit serum or plasma in a plastic transport tube.

Storage Instructions

Submission/transport (<3 days): Room temperature. For storage beyond three days, specimen should be refrigerated or frozen.

Causes for Rejection

Gel-barrier tubes

Test Details

Use

Detect the presence of sulfonylurea class drugs

Methodology

Liquid chromatography/tandem mass spectrometry (LC/MS-MS)

Sulfonylurea Analysis, Urine

Expected Turnaround Time

10 - 14 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Specimen Requirements

Specimen

Urine (random)

Volume

5 mL

Minimum Volume

1.2 mL

Container

Plastic urine container without preservative

Collection

Do not use preservative.

Storage Instructions

Submission/transport (<3 days): Room temperature. For storage beyond three days, specimen should be refrigerated or frozen.

Causes for Rejection

Urine from preservative tube

Test Details

Use

Detect the presence of sulfonylurea class drugs

Methodology

Liquid chromatography/tandem mass spectrometry (LC/MS-MS)

Susceptibility Testing, Aerobic and Facultatively Anaerobic Organisms

Synonyms

Sensitivity Testing

Test Includes

Qualitative determination of an isolated organism antimicrobial susceptibility. Identification is required to perform or provide an accurate interpretation for susceptibility testing, it will be done at an additional charge if not provided by the client.

Expected Turnaround Time

3 - 8 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Related Information

Aerobic Identification and Susceptibility

Specimen Requirements

Specimen

Pure isolate of aerobic or facultatively anaerobic rapidly-growing organism. Testing of multiple isolates will result in additional fee(s).

Container

A swab transport inoculated with the isolate from a pure culture or agar slant in screw-cap container packed as an etiologic agent. Maintain subculture at submitting laboratory.

Storage Instructions

Maintain specimen at room temperature.

Causes for Rejection

Organism does not grow well on test media; isolated organism not provided; improper labeling. CLSI interpretive standards do not exist.

Test Details

Use

Determine antimicrobial susceptibility of organisms involved in infectious processes when the susceptibility of the organism cannot be predicted from its identity. The pattern of antibiotic susceptibility is sometimes used to monitor nosocomial infections such as methicillin-resistant Staphylococcus aureus and to evaluate or follow the development of resistance to new antimicrobial drugs.^1,2

Limitations

Interpretive criteria do not exist for all bacteria. Susceptible, intermediate, and resistant categories are based on levels of antibiotics achieved in the serum of people with normal kidney and liver function. Drugs concentrated in urine may be effective for urinary tract infection even when the categorical interpretation is resistant. Conversely, drugs that do not penetrate well to a poorly vascularized area may not be effective even though the interpretation is susceptible.

Methodology

Manual or automated MIC methodology

Additional Information

Susceptible: This category implies that an infection due to the strain may be appropriately treated with the dosage of antimicrobial agent recommended for that type of infection and infecting species, unless otherwise contraindicated. Intermediate: This category provides a “buffer zone,” which should prevent small, uncontrolled, technical factors from causing major discrepancies in interpretations (eg, species that should have few or no endpoints in this range, or drugs with in vitro results affected by media variation or drugs with narrow pharmacotoxicity margins). Resistant: Strains falling in this category are not inhibited by the usually achievable systemic concentrations of the agent with normal dosage schedules and/or fall in the range where specific microbial resistance mechanisms are likely (eg, β-lactamases), and clinical efficacy has not been reliable in treatment studies. Major Mechanisms of Bacterial Antimicrobial Resistance Enzymatic inactivation or modification of drug: • β-lactamase hydrolysis of β-lactam ring with subsequent inactivation of β-lactam antibiotics • Modification of aminoglycosides by acetylating, adenylating, or phosphorylating enzymes • Modification of chloramphenicol by chloramphenicol acetyltransferase Decreased drug uptake or accumulation • Intrinsic or acquired lack of outer membrane permeability • Faulty or lacking antibiotic uptake and transport system • Antibiotic efflux system (eg, tetracycline resistance) Altered or lacking antimicrobial target • Altered penicillin-binding proteins (β-lactam resistance) • Altered ribosomal target (eg, aminoglycoside, macrolide, and lincomycin resistance) • Altered enzymatic target (eg, sulfonamide, trimethoprim, rifampin, and quinolone resistance) Circumvention of drug action consequences • Hyperproduction of drug targets or competitive substrates (eg, sulfonamide and trimethoprim resistance) Uncoupling of antibiotic attack and cell death • Bacterial tolerance and survival in the presence of usually bactericidal drugs (eg, β-lactams and vancomycin)

Suxamethonium

Expected Turnaround Time

3 - 5 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Related Information

Individual Allergens

Specimen Requirements

Specimen

Serum

Volume

0.2 mL

Container

10 mL red-top tube or 10 mL gel-barrier tube

Storage Instructions

Room temperature

Stability Requirements

Temperature	Period
Room temperature	14 days
Refrigerated	14 days
Frozen	3 months
Freeze/thaw cycles	Stable x3

Test Details

Methodology

Thermo Fisher ImmunoCAP®

Systemic Lupus Erythematosus (SLE) Profile A

Synonyms

SLE
SLE Profile A

Test Includes

Antichromatin antibodies; anti-DNA (double-stranded) antibodies; anti-RNP antibodies; anti-Smith antibodies; anti-SS-A antibodies; anti-SS-B antibodies; rheumatoid factor

Expected Turnaround Time

1 - 3 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Specimen Requirements

Specimen

Serum

Volume

4 mL

Minimum Volume

2 mL

Container

Red-top tube or gel-barrier tube

Storage Instructions

Maintain specimen at room temperature.

Stability Requirements

Temperature	Period
Room temperature	14 days
Refrigerated	14 days
Frozen	14 days
Freeze/thaw cycles	Stable x3

Test Details

Methodology

See individual tests.

Reference Interval

See individual tests.

Systemic Lupus Erythematosus (SLE) Profile C

Synonyms

ENA + dsDNA + Sjögren
SLE
SLE Profile C

Test Includes

Anti-dsDNA (double-stranded) antibody, quantitative; Sjögren's anti-SS-A; Sjögren's anti-SS-B; Smith antibody

Expected Turnaround Time

Within 1 day

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Specimen Requirements

Specimen

Serum

Volume

1 mL

Minimum Volume

0.5 mL (Note: This volume does not allow for repeat testing.)

Container

Red-top tube or gel-barrier tube

Storage Instructions

Maintain specimen at room temperature.

Stability Requirements

Temperature	Period
Room temperature	14 days
Refrigerated	14 days
Frozen	14 days
Freeze/thaw cycles	Stable x3

Causes for Rejection

Hemolysis; lipemia; gross bacterial contamination; icterus

Test Details

Use

Sensitive assay for screening for ANAs in patients suspected of having SLE

Limitations

Low antibody levels may be found in diseases other than connective tissue disease.

Methodology

Multiplex bead flow cytometry

Expected Turnaround Time

Special Instructions

Expected Turnaround Time

Specimen Requirements

Specimen

Volume

Minimum Volume

Container

Collection

Storage Instructions

Stability Requirements

Causes for Rejection

Test Details

Use

Limitations

Methodology

Expected Turnaround Time

Related Information

Related Documents

Specimen Requirements

Specimen

Container

Collection

Storage Instructions

Causes for Rejection

Test Details

Use

Methodology

Synonyms

Expected Turnaround Time

Specimen Requirements

Specimen

Volume

Minimum Volume

Container

Collection

Storage Instructions

Patient Preparation

Causes for Rejection

Test Details

Use

Methodology

Reference Interval

Expected Turnaround Time

Related Documents

Specimen Requirements

Specimen

Volume

Minimum Volume

Container

Storage Instructions

Stability Requirements

Causes for Rejection

Test Details

Use

Limitations

Methodology

Additional Information

Synonyms

Special Instructions

Expected Turnaround Time

Related Documents

Specimen Requirements

Specimen

Volume

Minimum Volume

Container

Collection

Storage Instructions

Stability Requirements

Patient Preparation

Causes for Rejection

Test Details

Use

Methodology

Special Instructions

Expected Turnaround Time

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Specimen Requirements