Isolation of human and canine IgM utilizing protein A affinity chromatography

Human and canine high molecular weight IgM's were isolated employing a system of G-200 column chromatography and passage through a protein A Sepharose 4B column. Polyacrylamide Gel Electrophoresis (PAGE) analysis of the isolated immunoglobulin revealed polypeptides corresponding to mu and light immunoglobulin chains of IgM which were identified immunochemically as IgM. Ultracentrifugation studies revealed that the isolated immunoglobulin co-migrated with 19S IgM markers. This simple and efficient procedure may serve as an alternative to classical isolation procedures of IgM from certain mammalian species.