Isolation of human IgA and IgM from normal serum using polyethylene glycol precipitation and affinity chromatography

A simple method is described for the preparation of highly purified IgA and IgM from small volumes of human serum. Enriched IgM and IgA fractions were prepared by precipitation with 7% (w/v) and 14% (w/v) polyethylene glycol respectively. This was followed by affinity chromatography and gel filtration. The final recovery of both IgA and IgM was approximately 30%. The purified preparations obtained were characterized by immunoelectrophoresis, double immunodiffusion, radial immunodiffusion, radioimmunoassay and gel filtration.