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To view specimen requirements and codes please select your laboratory:

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Test Code


CPT Code(s)


Preferred Specimen(s)

1 mL serum collected in a red-top tube (no gel)
NOTE: Plasma collected in an EDTA (lavender-top) tube
is also acceptable.

Transport temperature: Room temperature

Minimum Volume

0.5 mL

Specimen Stability

Room temperature: 7 days
Refrigerated: 14 days
Frozen: 60 days


Chromatography/Mass Spectrometry

Performing Laboratory

QuestDiagnostics Nichols Valencia

Setup Days

Set up: Tue, Sat; Report available: 2-5 days

Report Available

2-5 days

Reference Range(s)

800-1600 ng/mL

Clinical Significance

Trazodone (Desyrel®) is a Triazolopyridine derivative unrelated in structure to tricyclic antidepressants. Trazodone is indicated for treatment of depression characterized by a prominent and persistant dysphoric mood that interferes with daily functioning.

LOINC®' Code(s)

The Result and LOINC information listed below should not be used for electronic interface maintenance with Quest Diagnostics. Please contact the Quest Diagnostics Connectivity Help Desk for more information at 800-697-9302.

NOTE: The codes listed in the table below are not orderable Test Codes.

Result NameLOINC CodeComponent Name

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 guidelines 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.

LOINC assignment is based on a combination of test attributes, including the method used by the performing laboratory. For tests not performed by Quest Diagnostics, codes are assigned by the performing laboratory.

* The tests listed by specialist are a select group of tests offered. For a complete list of Quest Diagnostics tests, please refer to our Directory of Services.