Like IgG1, IgG3 activates complement and has an affinity for fc receptors; thus IgG1 and IgG3 are the more effective of the IgG subclasses. An IgG3 deficiency is associated with Wiscott-Aldrich disease, systemic lupus erythematosus, juvenile diabetes mellitus, and peridontal infections. IgG anti-viral antibodies are restricted to IgG subclasses 1 and 3, with IgG3 antibodies being the first to appear in response to infection. 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. Do NOT freeze this product.