Depending on which company you use, you might not need to do that. I purified my proteins in denatured condition and the company it is fine for injection. So I just sent them the protein in 8M urea. And I got quite good antibodies. The problem is if you are going to affinity purify your antibody. If you are, then you will need to get protein in native condition. In my case, I lowered the IPTG concentration and lowered the temperature for induction and only got a tiny amount of protein. But that was enough for me to couple it to the beads and the affinity purification worked. And by the way the company that I used for antibody production is Cocalico. http://www.cocalicobiologicals.com/about.html