Testosterone, Free
CPT Code: 84402
Order Code: 1385
ABN Requirement: No
Specimen: Serum
Volume: 2.8 mL
Minimum Volume: 1.3 mL
Container:
Red-top (no gel) or Serum Separator Tube (SST)
Plasma collected in:
Sodium Heparin (green-top) tube, Lithium Heparin (green-top) tube
Collection:
Specify age and sex on test request form.
Red-top tube (no gel): Allow blood to clot at room temperature. Centrifuge to separate the serum from the cells and immediately pour serum into a plastic transport tube.
Serum separator tube: Allow blood to clot at room temperature, centrifuge, and remove serum from the gel immediately (not to exceed 48 hours) by pouring serum into a plastic transport tube.
Patient Information: Administration of STRENSIQ may interfere in certain assays and may falsely elevate values. For patients receiving STRENSIQ, consideration should be given to using alternate methods.
Transport: Store serum at 2°C to 8°C after collection and ship the same day per packaging instructions included with the provided shipping box.
Stability:
Ambient (15-25°C): 7 days
Refrigerated (2-8°C): 7 days
Frozen (-20°C): 2 years
Causes for Rejection: Gross hemolysis; Grossly lipemic
Methodology: Calculation, Immunochemiluminescence Assay, Chromatography/Mass Spectrometry
Turn Around Time: 3 to 4 days
Reference Range:
| Age | Male (pg/mL) | Female (pg/mL) |
| <1 year | Not Established | Not Established |
| 1-11 years | ≤1.3 | ≤1.5 |
| 12-13 years | ≤64 | ≤1.5 |
| 14-17 years | 4.0-100.0 | ≤3.6 |
| 18-69 years | 46.0-224.0 | 0.2-5.0 |
| 70-89 years | 6.0-73.0 | 0.3-5.0 |
| >89 years | Not Established | Not Established |
Pediatric data from Clin Endocrinol (1989) 31:201-207 and Acta Endocrinologica (1985) 109:276-280.
The concentration of free testosterone is derived from a mathematical model using total testosterone by LCMSMS, sex hormone binding globulin, and albumin.
Clinical Significance: Test is helpful in assessing testicular function in males, and in managing hirsutism and virilization in females.
The CPT codes provided are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.