ARUP's Laboratory Test Directory

Testosterone Free, Adult Male : 0070111

Mnemonic: FREE T2

Methodology: Quantitative Electrochemiluminescent Immunoassay
Total Testosterone and SHBG are measured and free testosterone is estimated from these measurements.
Performed: Sun-Sat
Reported: Within 24 hours
Specimen Required: Patient Prep: Collect specimen between 6-10 a.m.

Collect: Serum separator tube or green (lithium heparin).

Specimen Preparation: Separate serum from cells ASAP or within 2 hours of collection. Transfer 1 mL serum or plasma to an ARUP Standard Transport Tube. (Min: 0.4 mL)

Storage/Transport Temperature: Refrigerated.

Unacceptable Conditions: EDTA plasma.

Stability (collection to initiation of testing): After separation from cells: Ambient: 48 hours; Refrigerated: 1 week; Frozen: 2 months
Reference Interval:
Male:
14-15 years:  3-138 pg/mL
16-17 years:  38-173 pg/mL
18 years and older: 47-244 pg/mL

Tanner Stage IV:  35-169 pg/mL
Tanner Stage V:  41-239 pg/mL
Interpretive Data: The concentration of free testosterone is derived from a mathematical expression based on the constant for the binding of testosterone to sex hormone binding globulin (SHBG).
Note: This test is not recommended for females or children.  For testing on females or children refer to Testosterone Free, Females or Children (0081059).
CPT Code(s): 84402