Rabbits were inoculated with 8 purified γ2 multiple myeloma globulins. The antisera were tested for specificity by the Ouchterlony gel diffusion technique. The formation of a spur between the lines of the homologous myeloma globulin and normal γ2-globulin was an indication that the antiserum contained antibody against antigenic determinants lacking from normal γ2-globulin. These antisera were subsequently absorbed with normal γ2-globulins (either fraction II, γ2-globulin, or mixtures of γ2- and γ1-globulin) and retested for their ability to react with the homologous antigen and normal γ2-globulin. Retesting was done by the Ouchterlony method and by immuno-electrophoresis. Absorption with γ2-globulin or fraction II in the range of 2 to 10 mg per ml removed all reactivity with normal γ2-globulin up to 100 mg per ml, but zones of precipitate were still formed with as little as 0.1 mg per ml of the homologous antigen, even after absorption with fraction II at 100 mg per ml. Although these findings do not prove that myeloma globulins are lacking from normal serum, they suggest that their concentration is too low to be detected by the methods used, and that as much as 150 mg per ml of γ2-and γ1-globulins will not remove the antibody against the homologous myeloma globulin.