Test name: Cortisol
Order Code: CORT
Preferred Specimen: 2mL serum in a Serum Separator Tube (SST or Tiger-top)
CPT Code: 82533
Collection: Allow SST to clot in an upright position for 30 min, then centrifuge sample within 2 hours of collection. Transfer serum to a plactic transport tube. Freeze.
Special Instructions and Considerations: Samples should not be taken from patients receiving therapy with high biotin doses (i.e. > 5mg/day) until at least 8 hours following the last biotin administration. Pregnancy, contraceptives, and estrogen therapy give rise to elevated cortisol concentrations. In samples from patients who have been treated with prednisolone, methylprednisolone or prednisone, falsely elevated concentrations of cortisol may be determined. The time of sample collection must be taken into account when interpreting results due to the cortisol secretion circadian rhythm. Severe stress can also give rise to elevated cortisol levels.
Transport Temperature: Refrigerated
Specimen Stability: 24 hours under room temperature; 4 days refrigerated