Human anti-oncogene p21 protein ELISA Kit

The coated well immunoenzymatic assay for the quantitative measurement of serum P21 utilizes a monoclonal anti-P21 and a P21-HRP conjugate. The assay sample and buffer are incubated together with anti-P21 antibody coated plate for sixty and washed. The diluted P21-HRP conjugate is then added to each well and incubated. After the incubation period, the wells are decanted and washed three times. The wells are then incubated with a substrate for the enzyme. The product of the enzyme-substrate reaction forms a blue colored complex. Finally, a stopping 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 P21 concentration since P21 from samples and P21-HRP conjugate compete for the anti-P21 antibody binding site. Since the number of sites is limited, as more sites are occupied by P21 from the sample, fewer sites are left to bind P21-HRP conjugate. Standards of known P21 concentrations are run concurrently with the samples being assayed and a standard curve is plotted relating the intensity of the color (Optical Density) to the concentration of P21. The unknown P21concentration in each sample is interpolated from this curve.