Use purified and conjugated forms of Thermo Scientific Pierce Recombinant Protein A/G to detect antibodies, especially IgG isotypes, of many different species hosts in Western blotting, ELISA, IHC and other immunoassay protocols.
The extended Fc-binding properties of Protein A/G make it a popular tool in the investigation and purification of immunoglobulins. Protein A/G binds to all human IgG subclasses, IgA, IgE, IgM and to a lesser extent IgD; however, it does not bind mouse IgA, IgM or murine serum albumin. Protein A/G is an excellent tool for purification and detection of mouse monclonal antibodies from IgG subclasses without interference from these other serum proteins. Individual subclasses of mouse monoclonals are most likely to have stronger affinity to this chimeric protein than to either Protein A or Protein G.
- Contains four Fc-binding domains from Protein A and two from Protein G
- Provides binding for all antibody species and subclasses recognized by either Protein A or Protein G
Properties of Recombinant Protein A/G:
- Source: E. coli
- Molecular weight: 50,460 (Apparent MW by SDS-PAGE: 40,000-45,000)
- Form: salt-free powder
- A280 of 0.1% solution: ~0.505
- Isoelectric point (pI): 4.65
Gene fusion of the Fc-binding domains of Protein A and Protein G has resulted in production of a structurally and functionally chimeric protein with broader binding than either Protein A or Protein G alone. During fusion, the Protein G gene sequence coding for the serum albumin-binding site is eliminated. This protein is expressed in E. coli and secreted into the surrounding medium during fermentation. The product obtained is consistent in quality and yield because the bacterial host is engineered to be deficient in major proteolytic activities. Binding is less pH-dependent than either Protein A or Protein G alone, occurring well at pH 5 to 8.
- Sikkema, W.D. (1989). An Fc-Binding Protein. Amer. Biotech. Lab. 7:42.
- Eliasson, M., et al. (1988). Chimeric IgG-binding receptors engineered from staphylococcal protein A and streptococcal protein G. J. Biol. Chem. 263(9):4323-7.
Comparison of Protein A, G, A/G and L
Binding characteristics of Protein A, Protein G, Protein A/G and Protein L (Tech Tip #34)
Recombinant Protein A (and HRP conjugate)
Protein A Agarose Resins, Columns and Kits