IgM is found in normal plasma at a concentration of 1.2 to 4.0 mg/ml. It is the first immunoglobulin produced during the immune response, the first antibody in neonates, and is involved in pathogenesis of autoimmune diseases. A diminished level of IgM is associated with Wiskott-Aldrich syndrome. Prepared from plasma shown to be non reactive for HbsAG, anti-HCV, anti-HBc, and negative for anti-HIV 1 & 2 by FDA approved tests. >95percent pure by SDS-PAGE.