New classes of immunoglobulins have recently been characterized, and major classes divided into subclasses. Proteins of the known classes are structurally distinct and some differences in biologic properties are known, but the general significance of these immunoglobulins is as yet not clear. Prior to a study of the biologic functions of the individual classes of immunoglobulins, techniques must be available which will consistently yield relatively large amounts of pure immunoglobulin. Several methods for purifying γ globulin have been described (1–3), but many of them have limitations that make them unsatisfactory for obtaining a consistently pure product from sizeable quantities of serum (4, 5). It is unlikely that a one-step procedure can efficiently purify large amounts of protein and therefore it is necessary to select a combination of techniques that will work best to accomplish purification. The majority of methods for purification use separation on DEAE-cellulose as a major step in the procedure (6); others use zone electrophoresis in conjunction with ion exchange chromatography in a two-step procedure (7).