Synacthen Stimulation Test (Blood)

Testing Laboratory

Auckland Te Toka Tumai | Auckland Hospital

Department

Chemical Pathology

Delphic Registration Code (Alpha Code)

COR (pre-dose cortisol)
CORP (post-dose cortisol)

Test Code (Numeric Code)

0379

Laboratory Handling

Phlebotomy

The test can be performed at any time of the day.
PROCEDURE
1. Insert a butterfly needle into the vein. Withdraw the pre-synacthen cortisol sample: 5 mL blood into a heparin PST tube. Request "Cortisol" on the form, write the time, and send immediately to the laboratory.
If ACTH is required also collect 5 mL blood into a chilled EDTA tube (on ice).

2. Infuse 250 ug synacthen over 1 minute. The butterfly needle can now be removed or flushed with saline and kept in.

3. After 30 minutes, withdraw the post-synacthen cortisol sample: 5 mL blood into a heparin PST tube. Use a separate form, request "post-synacthen cortisol" , write the time, and send in a separate bag. (If the butterfly has been kept in, first withdraw enough blood to wash out the saline before collecting the blood sample; dilution with saline will give a false low result).

Registration

Synacthen Stimulation Test - Cortisol.
Two separate numbers and test codes are to be used as these samples are timed:
Pre: COR/3006
Post: CORP/0379

Sample Stability

24 hours at 20-25°C, 4 days at 2-8°C, 12 months at -20°C.

Associated Tests

Synonyms

ACTH Stimulation Test, Post-synacthen cortisol, SST, short synacthen test

Turnaround Time

3 hours

Specimen Type

  • Plasma

Specimen Requirements

Tube/Container Type:

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

5

Minimum Sample Volume (ml)

3.5

No of Samples Required

1

Paediatric Specimen Requirements

Tube/Container Type:

Preferred
  • Lithium Heparin PST- Gel (Light Green Cap)
Acceptable
  • Plain (Red Top)
Preferred Sample Volume (ml)

0.5

Minimum Sample Volume (ml)

0.5

Pre-testing Requirements

The test can be performed at any time of the day.
The Synacthen is obtained from Pharmacy, not the laboratory. Synacthen is a synthetic form of ACTH.

Please refer:
Auckland Hospital Outpatient requests
to the Endocrinology Clinic at Greenlane Clinical Centre.
Requests from GPs for this test should be directed to the Endocrinology Outpatient Service at Greenlane Clinical Centre for booking (see Endocrine Nurse numbers).

Contact Information
Valerie Cheetham (Endocrine Nurse): Ext. 26871
Christine McGrail (Endocrine Nurse): Ext. 26854
Joan Callis (Endocrine Nurse): Ext. 26855

Additional Specimen Information

0.5 mL Paediatric Microtainer PST Blood (Preferred)
0.5 mL Paediatric Microtainer Plain Blood

Last updated: 18/09/2026