Cholecystokinin 18 (CCK18) ELISA Kit: This assay employs the competitive inhibition enzyme immunoassay technique. A monoclonal antibody specific to CCK18 has been pre-coated onto a microplate. A competitive inhibition reaction is launched between biotin labeled CCK18 and unlabeled CCK18 (Standards or samples) with the pre-coated antibody specific to CCK18. After incubation the unbound conjugate is washed off. Next, avidin conjugated to Horseradish Peroxidase (HRP) is added to each microplate well and incubated. The amount of bound HRP conjugate is reverse proportional to the concentration of CCK18 in the sample. After addition of the substrate solution, the intensity of color developed is reverse proportional to the concentration of CCK18 in the sample.