Now, if the antibody of interest, if that blue antibody is bound onto that red antigen, then our enzyme linked antibody will bind onto this antibody as shown in that diagram. Now, in the next step, we basically want to first remove all the different types of molecules inside that sample that are not bound to anything. And so once we wash our sample, we remove anything that is not bound. And once we wash, we then add that specific substrate, that specific molecule that is converted by this enzyme that is linked to our green antibody. And once we add our substrate, that enzyme will begin to transform that substrate to some type of product. And when that transformation takes place, that causes a color change in our sample.