Repeated affinity chromatography on glass beads with stable capacity: one-step purification of polyclonal IgA or IgM.

Absorption is an essential step in the purification of heterologous anti-idiotypic antibodies. Polyclonal immunoglobulins are preferentially used and have advantages in the absorption step since they have a broader antigenic spectrum than monoclonal immunoglobulin fractions. A method is described for the purification of polyclonal IgA and IgM by repetitive semi-automatic immunoaffinity chromatography using an LKB ultrograd gradient former. Anti-IgA or anti-IgM antibodies, respectively, were covalently bound to controlled pore glass beads. The capacities of the columns were stable during 20--24 absorption/elution cycles. IgA was isolated with a yield of 213 mg and a recovery of 15.2%. The purification factor was 15.2. IgM was isolated in a yield of 178 mg with a recovery of 41.9%. We thus achieved a purification factor of 38. For higher yields the number of cycles can easily be increased.