IgG2 is the only IgG subclass which passes through the placenta at a level generally lower than that found in the mother. A deficiency of IgG2 indicates a poor antibody response to bacterial polysaccharides and can lead to increased susceptibility to infections caused by encapsulated bacteria. Single arc by IEP against antisera to whole human serum and human IgG. No reaction to antisera to human IgA, IgD, IgE, or IgM. 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.