Triiodothyronine: Free T3

The Free T3 assay is a paramagnetic particle, chemiluminescent immunoassay for the quantitative determination of free triiodothyronine (T3) levels in human serum. The T3 hormone is synthesized from the thyroid gland after it is stimulated by Thyroid-Stimulating Hormone (hTSH). T3 is the major biologically active thyroid hormone which regulates normal growth and development by maintaining body temperature and stimulating calorigenesis. In addition, Free T3 affects carbohydrate, lipid, and vitamin metabolism. Measuring Free T3 is useful when altered levels of Total T3 occur due to changes in thyroid hormone binding proteins, especially in cases with altered Thyroxine Binding Globulin (TBG) or low albumin concentrations.