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Test Code UCORTM Cortisol, Free, 24 Hour, Urine

Additional Codes

Mayo CORTU
Epic ID LAB568

 

Specimen Type

Urine


Necessary Information


24-Hour volume (in milliliters) is required.



Specimen Required


Supplies: Urine Tubes, 10-mL (T068)

Submission Container/Tube: Plastic urine tube

Specimen Volume: 5 mL

Collection Instructions:

1. Collect urine for 24 hours.

2. Add 10 g of boric acid as preservative at start of collection.

Additional Information: See Urine Preservatives-Collection and Transportation for 24-Hour Urine Specimens for multiple collections.


UPH Waterloo Region Lab Test Catalog Note:

Collect a 24 hour urine sample. Keep sample refrigerated during collection period and return to the laboratory within 4 hours or less of completion of collection. Urine can be shipped refrigerated with no preservative. (10g. of boric acid or 25 mL of 50 % acetic acid can be used at the start of collection if not able to keep specimen refrigerated during collection or if unable to return within 4 hours of completion of collection.) 

Specimen Minimum Volume

3 mL

Specimen Stability Information

Specimen Type Temperature Time
Urine Refrigerated (preferred) 14 days
  Frozen  28 days
  Ambient  7 days
UPH Waterloo Region Lab Test Catalog Note:

Transport 5 mL of 24 hour urine refrigerated with total volume documented. 

Reject Due To

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

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Method Name

Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)

Useful For

Preferred screening test for Cushing syndrome

 

Diagnosis of pseudo-hyperaldosteronism due to excessive licorice consumption

 

Test may not be useful in the evaluation of adrenal insufficiency.

Day(s) Performed

Monday through Friday

Report Available

2 to 7 days

Reference Values

0-2 years: Not established

3-8 years: 1.4-20 mcg/24 h

9-12 years: 2.6-37 mcg/24 h

13-17 years: 4.0-56 mcg/24 h

≥18 years: 3.5-45 mcg/24 h

 

Use the factor below to convert from mcg/24 hr to nmol/24 hr:

 

Conversion factor

Cortisol: mcg/24 h x 2.76=nmol/24 hr (molecular weight=362.5)

 

For International System of Units (SI) conversion for Reference Values, see www.mayocliniclabs.com/order-tests/si-unit-conversion.html.

CPT Code Information

82530