Principe du test
Thyroxine ELISA Kit (A4930) employs the competitive enzyme immunoassay technique for the quantitative measurement of Thyroxine in serum, plasma, tissue homogenates, cell lysates, cell culture supernates or other biological fluids. The 96-well microtiter plate has been pre-coated with Thyroxine antigen. During the incubation, Thyroxine present in the samples or standards competes with the fixed amount of immobilized Thyroxine for binding sites on the Biotinylated Anti-Thyroxine Antibody. The more Thyroxine present in a sample or standard, the less Biotinylated Anti-Thyroxine Antibody that binds to the plate. Following incubation, unbound Biotinylated Anti-Thyroxine Antibody is removed by washing, and an HRP-Avidin conjugate is added to the wells and the microtiter plate is incubated. Following incubation and washing, TMB substrate solution is then used to visualize the HRP enzymatic reaction by catalysis to produce a blue-coloured product that changes to yellow after addition of acidic stop solution. The density of yellow is inversely proportional to the amount of Thyroxine present in each sample or standard. The concentration of Thyroxine can then be calculated by reading the O.D. absorbance at 450nm in a microplate reader and referring to the standard curve.