Test Overview
Clinical Utility
Free cortisol is useful in the detection of patients with Cushing’s syndrome for whom free cortisol concentrations are elevated.
Method
Chromatography/Mass Spectrometry
Specimen
Specimen Type
SerumContainers
Preferred Containers
Red top (no additive)
Acceptable Containers
Lavender top (EDTA)
Volume
Sample Volume
2.0 mL
Minimum Volume
0.7 mL
Stability
| Ambient | Refrigerated | Frozen |
|---|---|---|
| 2 days | 7 days | 730 days |
Rejection Criteria
| Criteria | Specification |
|---|---|
| Hemolysis | Gross |
| Specimen | Gel Separator tube |
Performance & Interpretation
Turnaround Time
12 days
Results
Name
Units
Reference Range
Conversion
-
CORTISOL,FREEmcg/dLAdult:
8:00 - 10:00 A.M.: 0.07 - 0.93
4:00 - 6:00 P.M.: 0.04 - 0.45
10:00- 11:00 P.M.: 0.04 - 0.35
Referral Location
Out-of-Country
Interface & Setup
HL7 Interface Codes
| Order Code | Result Name | Result Codes | Units |
|---|---|---|---|
| FCORTQST S | CORTISOL,FREE,LC/MS,S | 66072 | mcg/dL |
Test Version
Last Updated
2025-11-19