Testosterone, Free and Total, by Equilibrium Dialysis and Mass Spectrometry
Test Mnemonic
TESTTF
CPT Codes
- 84402 - QTY (1)
- 84403 - QTY (1)
LOINC ®
58952-3
Performing Laboratory
Cleveland Clinic Laboratories
Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 1.8 mL | Serum | Red Plain | Refrigerated | Allow specimen to clot. Centrifuge and transfer the serum to a plastic CCL tube within 2 hours of collection and refrigerate. |
Minimum Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 1 mL |
Stability
| Environmental Condition | Description |
|---|---|
| Refrigerated | 14 days |
| Ambient | 3 days |
| Frozen | 30 days |
Turnaround Time
2 - 5 days
Methodology
| Name | Description |
|---|---|
| Equilibrium Dialysis | |
| Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) |
Special Info
Free testosterone is directly measured after equilibrium dialysis by liquid-chromatography and tandem mass spectrometry (LC-MS/MS).Â
Clinical Info
This test measures testosterone and direct free testosterone concentrations using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and equilibrium dialysis (ED). It may be used to assess patients with suspected increased or decreased biologically active testosterone, including those with sex hormone-binding protein abnormalities, cisgender women, children, cisgender men with hypogonadism, and for monitoring patients on testosterone-suppressing therapy.
Clinical Limitation
Tanner Stage reference intervals are not yet established.Â