Recombinant Protein G (rProtein G) Agarose is suitable for purification of IgG antibodies using column chromatography or immunoprecipitation methods. This matrix, which contains a genetically engineered form of streptococcal protein G, is designed to eliminate binding of serum albumin while maintaining efficient binding of the Fc region of IgG isotypes. rProtein G is produced in E. coli and, after purification, is covalently immobilized on 4% agarose beads by cyanogen bromide. rProtein G Agarose binds to a broader range of IgG isotypes than react with protein A. rProtein G Agarose can bind >18 mg of human IgG/ml of gel. The binding characteristics and stability of rProtein G Agarose facilitate rapid and repeated use for affinity chromatography.