So once we form these two bands, we can now isolate these two proteins. So we take out this protein, place them into beaker one. We take out the second protein, the second polypeptide chain, and place it into beaker number two. So now we have two beakers with these two different polypeptide chains. And now all we have to do in step three is do exactly what we did follow the same exact procedures that we followed with those individual polypeptide chains, as we discussed previously. So what that means is, for example, let's suppose we take that beaker number one that contains our green polypeptide chain.