Ovine immunoglobulin M was isolated from sheep serum using gel filtration and affinity chromatography. Polyclonal and monoclonal antibodies against this isotype were prepared. The specificity of the monoclonal antibody was investigated using SDS-Page, immunoblotting, an enzyme-linked immunosorbent assay (ELISA) and affinity chromatography. On immunoblotting, monoclonal anti-IgM reacted with a 70 kD protein which corresponded to ovine IgM
