Turnaround Time: 1 - 2 days
CPT Code:


Test Type: 0.8 mL AM specimen and 0.8 mL PM specimen Serum
Stability Time:



Room temperature

14 days


14 days


14 days

Freeze/thaw cycles

Stable x3

Reference Range:

AM: 6.2−19.4 μg/dL; PM: 2.3−11.9 μg/dL


Collection Details:

Collection Instructions:

Submit two specimens on the same test request form (one collected in the AM and one in the PM as directed by the ordering physician). Print collection times and dates for both specimens on the individual tubes and in clinical information.

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.

Red-top tube or gel-barrier tube.

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

Room temperature.