Test Details
Methodology
Free: Direct analog enzyme immunoassay (EIA); Total: electrochemiluminescence immunoassay (ECLIA)
Result Turnaround Time
4 - 7 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Use
Evaluate hirsutism and masculinization in women; evaluate testicular function in clinical states where the testosterone binding proteins may be altered (obesity, cirrhosis, thyroid disorders); see individual test descriptions for more information
Special Instructions
State patient's age and sex on the test request form.
This panel includes Testosterone, Total, which may exhibit interference when sample is collected from a person who is consuming a supplement with a high dose of biotin (also termed as vitamin B7 or B8, vitamin H, or coenzyme R). It is recommended to ask all patients who may be indicated for this test about biotin supplementation. Patients should be cautioned to stop biotin consumption at least 72 hours prior to the collection of a sample.
Limitations
A pediatric reference interval has not been established for the direct free testosterone test.
Specimen Requirements
Specimen
Serum
Volume
2 mL
Minimum Volume
1 mL (Note: This volume does not allow for repeat testing.)
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.
Stability Requirements
| Temperature | Period |
|---|---|
| Room temperature | 14 days |
| Refrigerated | 14 days |
| Frozen | 14 days |
| Freeze/thaw cycles | Stable x3 |
Storage Instructions
Room temperature
Causes for Rejection
Gross lipemia (may yield erroneously high free testosterone results); plasma specimen; gross hemolysis and/or gross icterus cause for rejection of direct free testosterone
LOINC® Map
| Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
|---|---|---|---|---|---|---|
| 140103 | Testosterone,Free and Total | 58952-3 | 004227 | Testosterone | ng/dL | 2986-8 |
| 140103 | Testosterone,Free and Total | 58952-3 | 144981 | Free Testosterone(Direct) | pg/mL | 2991-8 |
| Order Code | 140103 | |||||
| Order Code Name | Testosterone,Free and Total | |||||
| Order Loinc | 58952-3 | |||||
| Result Code | 004227 | |||||
| Result Code Name | Testosterone | |||||
| UofM | ng/dL | |||||
| Result LOINC | 2986-8 | |||||
| Order Code | 140103 | |||||
| Order Code Name | Testosterone,Free and Total | |||||
| Order Loinc | 58952-3 | |||||
| Result Code | 144981 | |||||
| Result Code Name | Free Testosterone(Direct) | |||||
| UofM | pg/mL | |||||
| Result LOINC | 2991-8 |