Test Code LAB173 Testosterone Total and Free, Includes SHBG
Clinical Information
Free testosterone concentration is calculated using total testosterone (measured by immunoassay) and the binding constant of testosterone and sex hormone-binding globulin (SHBG). Testosterone immunoassays are both 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. For assays employing antibodies, the possibility exists for interference by human anti-animal antibodies (i.e., heterophile antibodies) in the patient sample. Patients who have been regularly exposed to animals or have received immunotherapy or diagnostic procedures utilizing immunoglobulins or immunoglobulin fragments may produce antibodies, (eg, HAMA), that interfere with immunoassays. This may falsely elevate or falsely decrease the results.
Synonym
- TESTOS
- SHGB
Profile Information
Reporting Name | Available Separately | Always Reported |
---|---|---|
Testosterone | Yes | Yes |
Sex Hormone Binding Globulin | Yes | Yes |
Free Testosterone | No | Yes |
Specimen Required
Preferred Container/Tube: Gold SST Top
Acceptable Container/Tube: Gold SST Top, Mint Green Top
Specimen Volume: 3 mL
Specimen Minimum Volume: 1 mL
Specimen Stability Information
Ambient: 4 hours (separated from cells)
Refrigerated: 5 days
Specimen Collection Information
Due to stability requirement for SHBG, serum/plasma should be physically separated from cells by centrifuging as soon as possible with a maximum limit of 2 hours from time of collection. For outpatient sites, centrifuge the sample as soon as possible with a maximum limit of 2 hours from time of collection. Send the spun primary tube to main lab refrigerated if the tube has a gel barrier; do not pour off.
Rejection Due To
- Gross hemolysis
Reference Values
FEMALE | MALE |
---|---|
Testosterone 0-6 months: 20-80 ng/dL
Sex Hormone Binding Globulin
Free Testosterone 0-365 days: ≤0.25 ng/dL |
Testosterone 0-6 months: 75-400 ng/dL
Sex Hormone Binding Globulin
Free Testosterone |
Performing Lab
Clinical Lab UH
Day(s) Performed
Monday through Sunday
Report Available
2 to 4 days
Reporting Name
Testosterone
Sex Hormone Binding Globulin
CPT Code Information
84403
84270
LOINC Code Information
2986-8
13967-5
2991-8