Dexamethasone Suppression Test

Testing Laboratory

Auckland Te Toka Tumai | Auckland Hospital

Department

Chemical Pathology

Delphic Registration Code (Alpha Code)

COR

Test Code (Numeric Code)

3006

Laboratory Handling

Phlebotomy

See pre test information please

Registration

Must see additional information for right registration code for external and internal samples

Sample Stability

-

Synonyms

Plasma/Serum Dexamethasone suppression test

Turnaround Time

1 day

Specimen Type

  • Plasma
  • Serum

Specimen Requirements

Tube/Container Type:

Preferred
  • Lithium Heparin PST- Gel (Light Green Cap)
Acceptable
  • Lithium Heparin - Non-gel (Green Cap)
  • Plain (Red Top)
  • SST II (Gold Cap)

Paediatric Specimen Requirements

Tube/Container Type:

Preferred
  • Lithium Heparin - Non-gel (Green Cap)
Acceptable
  • Lithium Heparin PST- Gel (Light Green Cap)
  • Plain (Red Top)
  • SST II (Gold Cap)

Pre-testing Requirements

Specimen Collection
LOW DOSE OVERNIGHT DEXAMETHASONE SUPPRESSION TEST

SPECIMEN:

Day 1: 0900h: 5 mL blood. PST tube preferred. Request " cortisol ".

2300h: Give 1 mg dexamethasone, orally.

Day 2: 0900h: 5 mL blood. PST tube preferred. Request "post-dexamethasone cortisol ".

Additional Specimen Information

Day 1: 0900h: 5 mL blood. PST tube preferred. Request " cortisol ".

2300h: Give 1 mg dexamethasone, orally.

Day 2: 0900h: 5 mL blood. PST tube preferred. Request "post-dexamethasone cortisol ".

Last updated: 26/03/2026