An improved method for the purification of rat serum albumin: removal of contaminants by concanavalin A-Sepharose.

Minor contaminants occasionally found in conventionally prepared rat serum albumin were easily and completely removed by concanavalin A-Sepharose chromatography. The unadsorbed fraction from a concanavalin A-Sepharose column contained albumin which was homogeneous on polyacrylamide gel electrophoresis. The recovery of albumin form rat serum was approximately 30%. Approximately 2% of the added protein obtained as an albumin peak in DEAE-cellulose chromatography was adsorbed on and eluted with alpha-methyl-D-glucoside from the concanavalin A-Sepharose column, and resolved into three components by gel electrophoresis. There was one major glycoprotein, possibly alpha 1-antitrypsin, and two minor proteins one of which was albumin.