skip navigation

Test Identifier Information

Registration CodeACTH

Roche Cobas e411

Diagnostic Use / Indications

ACTH in conjunction with cortisol is used to diagnose adrenal gland problems and pituitary diseases such as Cushing's disease/syndrome, Addison's, adrenal and pituitary tumours. ACTH is usually done as a diagnostic test once an abnormal cortisol level is detected.

External Price$51.69(Exclusive of GST)

Specimen Collection

Pre-Testing Requirements

Patient - need not be fasting but should be unstressed. A difficult venepuncture may cause increased ACTH secretion. Time of sampling must be stated (because of the diurnal variation in ACTH values) and the time of last dose of glucocorticoid (where relevant). In patients with Cushing's Syndrome it may be useful to take samples at 0900 hr and 2400 hr. Insulin hypoglycaemia or metyrapone testing are necessary when assessing hypothalamic - pituitary function.

Specimen Collection Protocols

Take 3 mL of EDTA anti-coagulated blood (purple top tube) and chill immediately in an ice/water mixture for 10 - 30 minutes, then centrifuge cold. Freeze plasma immediately. Even slight hemolysis must be avoided.

Patient SpecimenBlood, 3 mL EDTA (Lavender)). Chill in ice/water.
Paediatric SpecimenBlood 1 mL EDTA (must get 0.5 mL plasma).
Sample Delivery to LabWhole blood (which must be kept in ice/water).

Instructions for Referral to CHLabs

Aliquot Instructions>0.5 mL Plasma. No haemolysis! Freeze separated plasma for ACTH.
Aliquot Transport to CHLFrozen (as a separate tube for ACTH only)

CHLabs Laboratory

DepartmentEndocrinology Laboratory
Contact Details Email Email
This e-mail address is being protected from spam bots, you need JavaScript enabled to view it
Contact Phone Number(03) 3640886 | x80886
Test AvailabilityWeekly
Turnaround Time2 - 7 days
Reference Interval

1.0 - 12 pmol/L (7 - 10am)


Low ACTH results will be given by even slightly hemolysed samples.

Raised values - stress, Cushing's Syndrome, (hypothalamic-pituitary disease or ectopic ACTH secretion from a tumour), ACTH secreting pituitary tumours with hyper pigmentation, (Nelson's Syndrome), Addison's Disease, Adrenal enzyme deficiency, adrenalectomy.

Undetectable values - Cushing's Syndrome (adrenal adenoma or carcinoma) glucocorticoid therapy. Note that ACTH values may be undetectable in normal individuals, particularly in the late evening.

Uncertainty of Measurement



Additional Information

A sample for ACTH must be sent in a tube for ACTH analysis only (no shared samples). ACTH is very sensitive to hemolysis, but the rate of loss is reduced by chilling (but not freezing) blood, and by freezing plasma. Hemolysis as slight as 0.2 g/L Hb can cause significant loss of ACTH (Livesey and Dolamore, Clinical Biochemistry 43:1478-80 (2010)).

ACTH is rapidly destroyed by plasma enzymes - serum, heparin and fluoride samples are not acceptable as results are lowered. Warm thawed samples may not be assayed. Thawing and re-freezing the sample may elevate the levels.

Conversion factor: pg/ml = 4.5 x pmol/L

Delphic Number Test Number5428

CHL Follow us on Facebook