Protein G Agarose
Protein G Agarose consists of recombinant protein G, which is produced in E. coli and after purification, is covalently immobilized onto 4% cross-linked agarose beads. Protein G agarose is suitable for the isolation of IgG antibodies using column or immunoprecipitation methods.
DNA sequencing of native protein G (from Streptococcal group G) has revealed two IgG-binding domains as well as sites for albumin and cell surface binding (1 - 6). Protein G has been designed to eliminate the albumin and cell surface binding domains to reduce nonspecific binding while maintaining efficient binding of the Fc region of IgGs. With the removal of these binding domains, Protein G can be used to separate albumin from crude human IgG samples.