Testosterone, Bioavailable and Total, Includes Sex Hormone-Binding Globulin (Adult Males or Individuals on Testosterone Hormone Therapy)
Also known as: BIO T
Use
This test provides a calculated value for bioavailable testosterone concentration using total testosterone measured by immunoassay. It is used to evaluate hypogonadism in cisgender males with total testosterone at the lower limit of normal, assess testosterone status in individuals with protein-binding abnormalities, or monitor testosterone hormone therapies. It is not recommended when low testosterone is expected, such as in children and cisgender females. For these cases, testing by mass spectrometry is advised.
Special Instructions
Collect specimen between 6-10 a.m. Use serum separator tube or green (lithium heparin). Allow serum specimen to clot, separate serum or plasma from cells as soon as possible or within 2 hours of collection.
Limitations
Testosterone immunoassays are imprecise and inaccurate at low testosterone concentrations, such as those found in children and cisgender females. For these individuals, testing by mass spectrometry is recommended. No reference intervals have been established for males younger than 14 years or for cisgender females.
FDA ApprovedNew York Approved
Methodology
Immunoassay (ECLIA)
Biomarkers
LOINC Codes
- 2991-8
- 15432-8
- 2986-8
- 2990-0
- 13967-5
Result Turnaround Time
1 day
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
2 mL
Minimum Volume
0.6 mL
Container
ARUP Standard Transport Tube
Collection Instructions
Collect specimen between 6-10 a.m. Use serum separator tube or green (lithium heparin). Allow serum specimen to clot, separate serum or plasma from cells as soon as possible or within 2 hours of collection.
Storage Instructions
Refrigerated.
Causes for Rejection
EDTA plasma
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 48 hours |
| Refrigerated | 1 week |
| Frozen | 2 months |