So we form the antibody antigen complex. And now in step C, we add that enzyme linked antibody that we synthesized in the laboratory setting, and we place it into our well. And if the antibody antigen complex is present, if this complex exists, then the green antibody that contains the enzyme E will essentially bind to that antigen. 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.