Description
Principle of the assay: FVIII-Ag ELISA kit applies the competitive enzyme immunoassay technique utilizing a monoclonal anti-FVIII-Ag antibody and an FVIII-Ag-HRP conjugate. The assay sample and buffer are incubated together with FVIII-Ag-HRP conjugate in pre-coated plate for one hour. After the incubation period, the wells are decanted and washed five times. The wells are then incubated with a substrate for HRP enzyme. The product of the enzyme-substrate reaction forms a blue colored complex. Finally, a stop solution is added to stop the reaction, which will then turn the solution yellow. The intensity of color is measured spectrophotometrically at 450nm in a microplate reader. The intensity of the color is inversely proportional to the FVIII-Ag concentration since FVIII-Ag from samples and FVIII-Ag-HRP conjugate compete for the anti-FVIII-Ag antibody binding site. Since the number of sites is limited, as more sites are occupied by FVIII-Ag from the sample, fewer sites are left to bind FVIII-Ag-HRP conjugate. A standard curve is plotted relating the intensity of the color (O.D.) to the concentration of standards. The FVIII-Ag concentration in each sample is interpolated from this standard curve