BPTISynonyms: The microplate provided in this kit has been pre-coated with a monoclonal antibody specific to Aprotinin (AP). A competitive inhibition reaction is launched between biotin labeled Aprotinin (AP) and unlabeled Aprotinin (AP) (Standards or samples) with the pre-coated antibody specific to Aprotinin (AP). 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 Aprotinin (AP) in the sample. Then the mixture of substrate A and B is added to generate glow light emission kinetics. Upon plate development, the intensity of the emitted light is reverse proportional to the Aprotinin (AP) level in the sample or standard.