Principle of Sandwich Chemiluminescent Immunoassay(CLIA)

Sandwich CLIA is a kind of detection method combined double antibdoy sandwich method with chemiluminescence detecion method. It regualrly includes lots of steps, which are shown below. At first, the microtiter plate has been pre-coated with an antibody specific to analyte. Then, standards or samples are added to the appropriate microtiter plate wells, the analyte in standards and samples will bound to the immobilized Ab. Next, biotin-conjugated antibody is added and binds to the analyte absorbed on the plate. The complex of two antibodies and analytes in the wells act as a “sandwich” structure. After the unbound biotin-conjugated antibody is washed away, avidin-conjugated Horseradish Peroxidase (HRP) is added to each microplate well, after incubation, luminol is added into the microwells, and then relative luminosity values (RLU) will be scanned by photon counter reader. 

The principle scheme is listed below.: