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Test Code
DIHFT
Test Name
Dihydrotestosterone, Free and Total
CPT Codes
84999
Included Tests
  • Dihydrotestosterone
  • DHT, Percent Free Dialysis
  • DHT, Free
Expected Turnaround Time
9 - 15 days
Clinical Utility

Dihydrotestosterone measurement is used to diagnose 5α-reductase deficiency and for the evaluation of androgen utilization. Dihydrotestosterone is produced by the reduction of testosterone by 5α-reductase in the target organs. Circulating dihydrotestosterone is tightly bound to sex hormone-binding globulin. The free fraction represents the dihydrotestosterone available to act on tissues.
Specimen and Container Info

Preferred Specimen Type: Serum

Alternate Specimen Type: Plasma

Preferred Collection Container: Gold Top, Serum Separator

Alternate Collection Container: Green Top (Sodium or Lithium Heparin) or Red Top, Plain

Desired Specimen Volume: 3 mL
Collection Instructions
  1. Collect a gold top, serum separator tube via venipuncture.
Processing and Submission Instructions
  1. Separate serum from cells within 4 hours of collection.
  2. Transfer 3 mL of serum to a clear aliquot tube (screw cap).
Transport Instructions

Transport to the laboratory refrigerated. 
Stability Requirements

Room Temperature

14 days

Refrigerated

14 days

Frozen

14 days

Freeze/Thaw Cycles

Stable x6
Causes for Rejection
  •  Grossly hemolyzed, icteric or lipemic
Methodology
Equilibrium Dialysis, Chromatography/Mass Spectrometry
Reference Intervals

See patient report.
Alternate Names
  • Free 5-α-dihydrotestoterone
Reference Lab
Labcorp Of America Holdings
Testing Schedule
Varies
The American Medical Association (AMA) Current Procedural Terminology (CPT) codes published by HNL Lab Medicine are guidelines and are intended for informational purposes only. CPT coding is the exclusive responsibility of the billing entity. View the Terms.
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