Principle of Assay
Rat Thyroxine/T4 ELISA Kit (A247022) is a 2 hour competitive Enzyme-Linked Immunosorbent Assay (cELISA) designed for the in vitro quantitative determination of rat Thyroxine/T4 in serum, plasma, tissue homogenates, and other biological fluids. A 96-well microtiter plate has been pre-coated with Thyroxine/T4. During the assay, Thyroxine/T4 present in the standards or samples competes with immobilized Thyroxine/T4 for binding to an assay-specific antibody. Following incubation, unbound components are removed by washing and HRP-Streptavidin conjugate is added to the wells. After further incubation and washing, TMB substrate solution is added to visualize the HRP enzymatic reaction. This produces a blue-coloured product that changes to yellow following addition of acidic stop solution. The intensity of the colour is measured at 450 nm using a microplate reader. The concentration of Thyroxine/T4 in the samples is inversely proportional to the OD450 value and is determined by comparison with the standard curve.