Quick, convenient preparative purification of monoclonal antibodies. Wellestablished protein Abased medium used in many approved MAb processes. Recombinant protein A exhibits similar Fc region specificity to that of native protein A but shows enhanced binding capacity and fewer regulatory concerns due to the total absence of mammalian culture in the ligand production and purification. Simple operations with a syringe, pump, or highperformance chromatography system, such as ÄKTA design. The recombinant protein A ligand (produced in E. coli) is coupled to Sepharose Fast Flow by a technique which generates a stable thioether linkage between rProtein A and the base matrix. The coupling technique is optimized to give high binding capacity for IgG.