Principle of Assay
Human PD1/PDL1 ELISA Kit (A303038) is a 4 hour competitive Enzyme-Linked Immunosorbent Assay (cELISA) designed for the in vitro quantitative determination of human PD1/PDL1 in serum, plasma, tissue homogenates, and other biological fluids. A 96-well microtiter plate has been pre-coated with PD1/PDL1. During the assay, PD1/PDL1 present in the standards or samples competes with immobilized PD1/PDL1 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 PD1/PDL1 in the samples is inversely proportional to the OD450 value and is determined by comparison with the standard curve.