Tryptophan | Test Detail | Quest Diagnostics

Tryptophan

Test Code

959

CPT Code(s)

82131

Test Code

959

CPT Code(s)

82131

Not offered in Quest Diagnostics Nichols Institute (IFD) – San Juan Capistrano. Please provide SERVICE AREA INFORMATION to find available tests you can order.

In-home collection is not available in your area through Quest Mobile.

Clinical Significance

Tryptophan

Test Resources

None found for this test
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Test Details

Patient Preparation

Collect plasma specimens after an overnight fast (or at least 4 hours after a meal) if possible.
Non-fasting samples are acceptable for pediatric patients.

Methodology

Chromatography/Mass Spectrometry

Assay Category

This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by FDA. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.

Reference Range(s)

≤30 days	17-85 umol/L
31 days-23 months	16-92 umol/L
2-17 years	30-94 umol/L
≥18 years	40-91 umol/L

LOINC® Codes, Performing Laboratory

Service Area must be determined

Patient Preparation

Collect plasma specimens after an overnight fast (or at least 4 hours after a meal) if possible.
Non-fasting samples are acceptable for pediatric patients.

Methodology

Chromatography/Mass Spectrometry

Assay Category

Reference Range(s)

≤30 days	17-85 umol/L
31 days-23 months	16-92 umol/L
2-17 years	30-94 umol/L
≥18 years	40-91 umol/L

LOINC® Codes, Performing Laboratory

Service Area must be determined

Preferred Specimen(s)

2 mL plasma collected in a sodium heparin (green-top) tube

Alternative Specimen(s)

Plasma collected in: EDTA (lavender-top) tube or lithium heparin (green-top) tube

Minimum Volume

0.25 mL

Collection Instructions

Separate plasma from cells as soon as possible and freeze below -20° C

Transport Container

Transport tube

Transport Temperature

Frozen

Specimen Stability

Room temperature: Unacceptable
Refrigerated: 7 days
Frozen: 28 days

Reject Criteria

Gross hemolysis

Setup Schedule

Service Area must be determined

Preferred Specimen(s)

2 mL plasma collected in a sodium heparin (green-top) tube

Alternative Specimen(s)

Plasma collected in: EDTA (lavender-top) tube or lithium heparin (green-top) tube

Minimum Volume

0.25 mL

Collection Instructions

Separate plasma from cells as soon as possible and freeze below -20° C

Transport Container

Transport tube

Transport Temperature

Frozen

Specimen Stability

Room temperature: Unacceptable
Refrigerated: 7 days
Frozen: 28 days

Reject Criteria

Gross hemolysis

Setup Schedule

Service Area must be determined

Not offered in Quest Diagnostics Nichols Institute (IFD) – San Juan Capistrano. Please provide SERVICE AREA INFORMATION to find available tests you can order.

In-home collection is not available in your area through Quest Mobile.

Test Details

Clinical Significance

Test Resources

Reference ranges are provided as general guidance only. To interpret test results use the reference range in the laboratory report.

The CPT codes provided are based on AMA guidance and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.

This material contains content from LOINC® (http://loinc.org). The LOINC Table, LOINC Table Core are copyright © 1995-2019, Regenstrief Institute, Inc. and the Logical Observation Identifiers Names and Codes (LOINC) Committee and is available at no cost under the license at http://loinc.org/license.

The tests listed by specialty and category are a select group of tests offered. For a complete list of Quest Diagnostics tests, please adjust the filter options chosen, or refer to our Directory of Services.