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PTD - 151

Test Directory -  ACTH



Clinical Indications

Establishing the aetiology of proven Cushing's syndrome or differentiation between primary and secondary adrenal insufficiency (sample taken at 9.00 hrs). ACTH levels are not useful in monitoring steroid replacement therapy.

Request Form 

Combined Pathology Blood form (Yellow/Black or Blue for GP's)


Referred test: Analysed by Biochemistry, Royal London Hospital if specific criteria met.

Specific Criteria

Requested by Consultant Endocrinologists or if agreed with Consultant Biochemist for investigation of proven Cushing's or adrenal insufficiency.

Patient Preparation

Samples should be taken between 09.00 and 10.00 hrs

Turnaround Time

2 weeks




2 ml


Pink top (EDTA) or

Red top (EDTA) tube for paediatrics.

Samples must be transported to the laboratory immediately.

Causes for Rejection

Not meeting specific criteria for analysis. Delay in sample reaching laboratory.

Reference Range

09.00 hrs sample: Less than 50 ng/L


Provided by the referral laboratory if sufficient clinical details are given and a cortisol result is provided.

Lab. Handling

Processing: Centrifuge and aliquot immediately into 2 tubes and freeze at    -20C in separating freezer (CB40), active frozen rack 110.
ACTH and send or NOACT and save in separating freezer (CB40) at -20C, saved frozen rack.

Version 1.0 / April 2014                                                                                                          Approved by: Consultant Biochemist