The Autobio f-T3 CLIA test kit is intended for the quantitative determination of free triiodothyronine (f-T3) concentration in human serum.
Triiodothyronine, a thyroid hormone, circulates in blood almost completely bound (>99.5%) to carrier proteins. The main transnport protein is thyroxine-binding globulin (TBG). Howerer, only the free (unbound) portion of triiodothyronine is believed to be responsible for the biological action. Further, the concentrations of the carrier proteins are altered in many clinical conditions, such as pregnancy. In normal thyroid function as the concentrations of the carrier proteins alter, the total triiodothyronine level changes so that the free triiodothyronine concentrations remains constant. Thus, measurements of free triiodothyronine concentrations correlate more reliably with clinical status than total triiodthyronine levels. For example, the increase in total triiodothyronine levels associated with pregnancy, oral contraceptives and estrogen therapy result in higher total T3 levels while the free T3 concentration remains basically unchanged.
This CLIA test provides the technician with optimum sensitivity while requiring few technical manipulations in a direct determination of free T3.
