Protein G is a cell wall protein from group C and G Streptococci with a molecular weight between 40-65 kDa and shows high specificity for the Fc region of immunoglobulin G molecules of many mammalian species. The quality of the resin (Protein G Agarose or equivalent) and stability of the immobilisation is important to avoid leakage of Protein G during the elution procedure.

Protein G affinity chromatography is a rapid one-step purification, which removes most non IgG contaminants and can achieve purities close to homogeneity. It is particularly useful for purifications of tissue culture supernatant, where 10-100 fold concentrations can be achieved.

Antibody samples purified using this affinity resin may be used in a wide range of laboratory procedures such as 1D or 2D polyacrylamide gel electrophoresis, Western blotting, ELISA etc. Binding affinity varies depending upon the source species and subclass. See our website for further details.