Free Androgen Index (FAI)
Also known as: Testosterone:SHBG Ratio
Use
The free androgen index can be used to estimate physiologically active testosterone.
Special Instructions
State the patient's age and sex on the test request form. Patients should be cautioned to stop biotin consumption at least 72 hours prior to the collection of a sample as this test may exhibit interference if the sample is collected from a person consuming a high dose of biotin.
Limitations
This test may exhibit interference when the sample is collected from an individual consuming a supplement with a high dose of biotin. Biotin can interfere with the assay performance, leading to inaccurate results. It is important to inform patients to stop biotin consumption at least 72 hours before sample collection to reduce the risk of interference and ensure accurate test results.
Methodology
Immunoassay (ECLIA)
Biomarkers
LOINC Codes
- 13967-5
- 24125-7
- 2986-8
Result Turnaround Time
1 day
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.8 mL
Container
Red-top tube or gel-barrier tube
Collection Instructions
If a red-top tube is used, transfer separated serum to a plastic transport tube.
Storage Instructions
Room temperature
Causes for Rejection
Plasma specimen
Other tests from different labs that may be relevant