The Bio-Rad Anti-Human Globulin Reagents include Anti-Human Globulin: Anti-IgG and Anti-Human Globulin: Anti-IgG, -C3d (polyspecific). The Anti-IgG component is derived from rabbits while the Anti-C3d is a monoclonal IgM antibody. Both reagents are colored green to enhance process control. The reagents are used in the direct antiglobulin test to demonstrate the in vivo coating of human red blood cells with antibody and/or complement components in the case of the polyspecific AHG reagent. The reagents may also be used to demonstrate the in vitro coating of human red blood cells with antibody molecules and/or complement (polyspecific AHG only). Assays may include antibody screening, antibody identification, weak D testing, antiglobulin crossmatch and rare antigen typing.