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HelpTest Code COR Cortisol, serum, random
Laboratory Code
LAB61
Specimen Requirements
Specimen Type: Serum
Container/Tube: Gold Top (SSTII)
Volume: 5.0 mL
Minimum Volume: 0.5 mL serum
Collection Instructions: Allow specimen to clot for 30 mins and centrifuge within 2 hrs.
Specimen Stability
| Specimen Type | Serum |
|---|---|
| Ambient | 8 hours |
| Refrigerate | 14 days |
| Frozen | 30 days |
Methodology
Chemiluminescent Immunoassay
Days and Times Performed
24 hrs, TAT 1 day
Specimen Condition
| Gross Haemolysis | Alert/Reject |
|---|---|
| Icterus | OK |
| Lipaemia | OK |
| Others | Not applicable |
Reference Interval
Serum cortisol is time dependent.
Paediatric:
| Age | |
|---|---|
| 2 – 14 days | 13 – 340 nmol/L |
| 15 days – < 1 yr | 14 – 458 nmol/L |
| 1 yr – 8 yrs | 48 – 297 nmol/L |
| 9 – 13 yrs | 61 – 349 nmol/L |
| 14 – 16 yrs | 77 – 453 nmol/L |
| 17 – 18 yrs | 97 – 506 nmol/L |
Adult:
Cortisol 8am: 102 - 535 nmol/L
Cortisol 12 Midnight: 80 - 477 nmol/L
Testing Laboratory
National University Hospital
Clinical Chemistry, 67724346
Useful For
Differential diagnosis of Cushing syndrome.
Screening and diagnosis of primary and secondary adrenal insufficiency.
Service Code
31721
LOINC Code Information
83090-1
Update
Last updated 11/03/2025