AFFINITY PURIFICATION OF ANTIBODIES USING IMMUNOMICROSPHERES

Antigen-immobilized colloidal particles (immunomicrospheres) of submicrometer size were used for the immunoaffinity separation of antibodies. Carboxylated latex particles (P(St/AAm)-H) were prepared by copolymerization of styrene (St)/acrylamide (AAm) and by subsequent hydrolysis and were coupled covalently with antigen (bovine serum albumin; BSA) by the carbodiimide method. The anti-BSA antibody binding capacity of the immunomicrospheres increased with increasing amount of immobilized BSA up to the value which corresponds to the high packing density of the antibody molecules on the surface. The binding ratios of the immunomicrospheres, defined as the ratio of mol antibody adsorbed to mol BSA immobilized, were comparative to those of the conventional immunoadsorbents for affinity chromatography and did not decrease during repeated cycles of adsorption and desorption. By use of the immunomicrospheres, the antibodies were successfully purified from antisera.