Protein A/G

Protein A is a 42 kDa surface protein originally found in the cell wall of the bacterium Staphylococcus aureus. It can bind immunoglobulins. Protein G is an immunoglobulin-binding protein expressed in group C and G Streptococcal bacteria. Protein A/G is a genetically engineered protein that combines the IgG binding profiles of both Protein A and Protein G. It is a gene fusion product. Recombinant fusion protein A/G contains 6× His-tag on the N-terminus, five Ig-binding regions of protein A fusion with three Ig-binding region of protein G. Cell wall binding region, albumin binding region and other non-specific binding regions have been eliminated from the fusion protein A/G to ensure the maximum specific IgG binding. 6× His-tag on N-terminus can be used for affinity purification or for protein A/G detection using anti-His-tag antibody. Protein A/G binds to all IgG subclasses from various mammalian species, including all IgGs that bind to both Protein A and Protein G, making it the ideal choice for purification of all kinds of polyclonal or monoclonal IgG antibodies.