Principle of Assay
Human Carbohydrate Antigen 19-9 ELISA Kit (A3090) employs the sandwich enzyme immunoassay technique for the quantitative measurement of human Carbohydrate Antigen 19-9 in serum, plasma, tissue homogenates, cell lysates, cell culture supernates or other biological fluids. An antibody specific for Carbohydrate Antigen 19-9 has been pre-coated onto a 96-well microtiter plate. The standards and test samples are added into the wells and the Carbohydrate Antigen 19-9 present in each sample is bound to the wells by the immobilized antibody. Following incubation, the wells are washed and then incubated with Biotinylated Anti-Carbohydrate Antigen 19-9 Antibody, which binds the captured Carbohydrate Antigen 19-9 present in each well. HRP-Avidin conjugate is then 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 proportional to the amount of Carbohydrate Antigen 19-9 captured in each well. The concentration of Carbohydrate Antigen 19-9 can then be calculated by reading the O.D. absorbance at 450nm in a microplate reader and referring to the standard curve.