Triiodothyronine (T3), Free
Also known as: Free T3, T3, Free
Use
Evaluate thyroid function and assess abnormal binding protein disorders
Special Instructions
Patients should be queried regarding biotin supplementation since this test may show interference when the blood sample is collected from someone taking high doses of biotin (vitamin B7, B8, vitamin H, or coenzyme R). Patients should discontinue biotin consumption at least 72 hours before the sample collection.
Limitations
The test may exhibit interference from circulating antibodies to thyroid hormones, which have been reported to affect free hormone immunoassays. Moreover, this test does not account for biotin interference, which can result in inaccurate readings if not disclosed and managed prior to blood collection.
Methodology
Immunoassay (ECLIA)
Biomarkers
LOINC Codes
- 3051-0
- 3051-0
Result Turnaround Time
1-2 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.7 mL
Container
Red-top tube, gel-barrier tube
Collection Instructions
If a red-top tube or plasma is used, transfer the separated serum or plasma to a plastic transport tube.
Storage Instructions
Room temperature
Causes for Rejection
Citrate plasma specimen; improper labeling
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 14 days |
| Refrigerated | 14 days |
| Frozen | 14 days |