Triiodothyronine, Free (FT3)

Code

6180

Principle

T3 is the major biologically active thyroid hormone. Of the circulating T3, about 80% is formed from peripheral deiodination of thyroxine and 20% is secreted directly from the thyroid gland. The T4 and T3 hormones are transported in the circulation bound to thyroxine binding globulin (TBG), thyroxine binding pre-Albumin (TPBA) and albumin.

Preanalytical

1 mL Serum Refrigerated

Turn Around Time

1 day

Methodology

Chemiluminescent immunoassay (CLIA)

Limitations

The results  is susceptible to interference from high levels of biotin. The recommended daily intake for biotin is 30 μg. High doses of biotin (up to 30 mg per day) may be taken as a dietary supplement aimed at improving hair loss, nail growth, or skin condition.