Protein A/G/L-Sepharose is prepared by covalently coupling recombinant Protein A/G/L (Cat.# 6540; containing five Ig-binding regions of protein L, five IgG binding domains from Protein A , and three Ig-binding regions of protein G. Cell wall binding regions, albumin binding regions and other non-specific binding regions have all been eliminated from the fusion protein to ensure the maximum specific IgG binding) to 6% cross-linked sepharose beads. The coupling technique is optimized to give a high binding capacity. The capacity of IgG binding could be greater than 10 mg of human IgG per ml of wet bead.