There are three general categories of procedures employed for the quantitative determination of the gamma globulin content of biological fluids. These are (1) electrophoretic methods, (2) chemical procedures, usually based on salt or organic solvent precipitation, and (3) immunochemical methods. A fourth class of procedures which are qualitative or semi-quantitative in nature, are the flocculation reactions. These flocculation procedures are widely used in clinical work to determine changes in protein composition of disease sera, especially in gamma globulin, as compared to normal sera (1). The application of the electrophoretic technique of Tiselius to biological and medical problems has been fully discussed in recent review articles by Stern and Reiner (2), Luetscher (3) and Gutman (4). From a clinical viewpoint electrophoretic methods have the disadvantages of requiring relatively large amounts of protein material, expensive equipment, and skilled technical help and then permit only a few individual determinations to be per