Dihydrotestosterone
Dihydrotestosterone-13427
Hydroxy-5(Alpha)
Dihydrotestosterone and dihydrotestosterone/ratio may be used for differential diagnosis of diseases of sexual differentiation (DSD)
Submission of the minimum volume does not allow for repeat testing
Immediately following collection, thoroughly mix sample by gently inverting 5 times
- Allow sample to clot for a minimum of 30 minutes
- Spin within one (1) hour of collection
- Transfer serum to a Screw-cap polypropylene frozen transport vial/tube - 4mL (LabCorp), labelled as serum
- Freeze
Heparin plasma
Lavender/Dk green:
Immediately following collection, mix sample thoroughly by gentle inverting 8 - 10 times, to prevent clotting
Red:
- Allow sample to clot
- Spin within one (1) hour of collection
- Transfer serum to a Screw-cap polypropylene frozen transport vial/tube - 4mL (LabCorp), labelled as serum
- Freeze
Lavender/Dk green:
- Spin within one (1) hour of collection
- Transfer plasma to a Screw-cap polypropylene frozen transport vial/tube - 4mL (LabCorp), labelled as the appropriate plasma type
- Freeze
Frozen (preferred) - 19 months
Freeze/thaw cycles - stable x 6
Refrigerated - 7 days
Ambient - 7 days
High performance liquid chromatography (HPLC) with Tandem Mass Spectrometry
ng/dL
DHT levels may be inappropriately low compared to testosterone levels in 5a-reductase deficiency. It is recommended by guidelines to measure the ratio of testosterone to DHT. DHT levels may also be monitored to follow the effectiveness of 5a-reductase inhibitor testament in female alopecia.