So this enzyme linked antibody only binds to our antigen if it is bound itself to that blue antibody. And so if the antigen is present inside our mixture, we have this entire complex that is formed and notice it's like a sandwich, because we have two antibodies. And in between the antibody, we have our antigen. And so once again, as in step D, in step d for a sandwich allies that we wash our mixture to basically remove anything that is not bound. And because this is bound, this is not removed. And when we add our substrate into the mixture, because the enzyme will be present inside our solution, that enzyme will begin to readily convert that substrate into that product.