Test Catalog

Test ID: CRANR    
Cortisol, Free, Random, Urine

Specimen Type Describes the specimen type validated for testing


Ordering Guidance

The preferred screening test for Cushing syndrome is a measurement of free cortisol in a 24-hour urine collection by liquid chromatography-tandem mass spectrometry (LC-MS/MS); order CORTU / Cortisol, Free, 24 Hour, Urine.


The optimal specimen type for evaluation of primary adrenal insufficiency and hypopituitarism is serum; order CORT / Cortisol, Serum.

Specimen Required Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Supplies: Urine tube, 10 mL (T068)

Collection Container/Tube: Clean, plastic urine container with no metal cap or glued insert

Submission Container/Tube: Plastic, 10-mL urine tube or clean, plastic aliquot container with no metal cap or glued insert

Specimen Volume: 10 mL

Collection Instructions: Collect a random urine specimen.

Specimen Minimum Volume Defines the amount of sample necessary to provide a clinically relevant result as determined by the Testing Laboratory

4 mL

Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected

  All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen TypeTemperatureTimeSpecial Container
UrineRefrigerated (preferred)14 days
 Frozen 28 days
 Ambient 7 days