An antibody specific to the Vip3A protein molecule is immobilized on the microwell plates and the second antibody
specific for Vip3A molecule is conjugated with horse radish peroxidase (HRP). When the sample extracts are
added to the microtiter wells, the Vip3A from sample binds to the antibody immobilized in the well. This binding
is subsequently detected by addition of an enzyme-labeled antibody. After a washing step, the substrate is added. The
enzymatic reaction and development of color are proportional to the amount of Vip3A present in the sample. The
reaction is terminated by the addition of stop solution. Absorbance is then measured on a plate reader.
