I'm from Brazil, I try to do some Western Blot with sera of patients and igM. I used the protocol with the BSA, non-fat milk and gelatin. All this protocols works with my positive control with igG. But when I made in the same experiment with my second antibody IgM did'nt work, I can't saw any bands, only the backgroud. I search for a protocol in this site and in the booka and I didn't see anything specific for igM, If someone have any idea or protocol for help me. Please, send me a e-mail.