Human CA19-9 Microsample ELISA Kit is a Sandwich-based immunoassay designed for the quantitative measurement of CA19-9 in Serum plasma tissue homogenates cell lysates cell culture supernates and other biological fluids It provides a detection range of 0 79-50 U/mL with a sensitivity of 0 28 U/mL The assay can be completed in approximately 3 5h The procedure follows a The test principle applied in this kit is Sandwich enzyme immunoassay The microtiter plate provided in this kit has been pre-coated with an antibody specific to Human CA19-9 Standards or samples are added to the appropriate microtiter plate wells then with a biotin-conjugated antibody specific to Human CA19-9 Next Avidin conjugated to Horseradish Peroxidase (HRP) is added to each microplate well and incubated After TMB substrate solution is added only those wells that contain Human CA19-9 biotin-conjugated antibody and enzyme-conjugated Avidin will exhibit a change in color