Method for separating serum albumin and gamma globulin

A method for the separation of gamma globulin from albumin contained in an aqueous solution of both by ultrafiltration using an altered substrate microfilter having a water permeability of 0.2-25 gallons per square foot per day per pound per square inch comprising a porous solid filter substrate one surface of which is impregnated with particulate solids affixed within the pores of the substrate having an average particle size of 0.1-0.5 micrometer at the feed interface, the aqueous solution being characterized in that the total concentration of protein in the aqueous solution is 0.1-2% by weight, the pH of the aqueous solution is 8-10 and the solution contains no more than 0.01 mole per liter of inorganic electrolyte, the albumin being enriched in the retentate and the gamma globulin being enriched in the permeate.