Protein A and protein G are bacterial immunoglobin (IgG) binding proteins. While, protein A is originated from Staphylococcus aureus, protein G is of Streptococcal origin. Rockland offers protein A and protein G in unconjugated and conjugated forms for common immunoassays including ELISA, western blotting, immunohistochemistry. Sepharose protein A, Sepharose protein G and Sepharose protein A/G are widely used for immunoprecipitation and IgG purification. While both protein A and protein G bind to immunoglobins from various species, their affinity differs in dependence of immunoglobin classes as well as species origins. See Binding Properties of Protein A and Protein G for more information.
Dot blot of human (1), rat (2) and dog (3) IgG using Protein G and Fluorescein rabbit anti-Protein G
Dot blot of human (1), Golden Syrian Hamster (2) and sheep (3) IgG using HRP Protein A conjugate
SEPHAROSE™ Protein A
Protein A (Uniprot P38507) is a 56 kDa cell wall protein originated from Staphylococcus aureus. It contains five homologous Ig-binding domains. Each domain is able to bind the Fc fragment of a wide range of mammalian immunoglobulins. Protein A affinity to Fc may vary in dependence of IgG species origins or subclasses (see table). Protein A is often coupled to solid matrixes such as Sepharose™, magnetic particles or latex for IgG purification from ascites, serum or hybridoma culture media. Protein A is often coupled with reporter molecules such as a fluorescent dye, enzymes, biotin, colloidal gold or radioactive iodine as serve as detection agents.
Suggested Protein A Products based on Applications
Protein A Peroxidase Conjugate for ELISA and western blotting Protein A Biotin Conjugate for ELISA, western blotting and IHC Protein A conjugated to different Dylight™ for FLISA and immunofluorescence microscopyProtein A Fluorescein Conjugate for FLISA and immunofluorescence microscopyProtein A Alkaline Phosphatase Conjugate for ELISA
Protein G (Uniprot P19909) is an immunoglobulin-binding protein from Streptococcal bacteria. As the native molecule also binds albumin, the albumin binding site has been removed from recombinant forms of Protein G. Much like Protein A, but with different IgG-binding specificities (see table), Protein G is often used for immunoglobin purification and detection. To broaden the IgG binding activity, recombinant protein A/G is also used (see Sepharose™ conjugates below). Protein G is often immobilized on solid surface such as Sepharose™, latex or magnetic particles for IgG purification from ascites, serum or hybridoma culture media. Protein G is also coupled with reporter molecules such as a fluorescein, peroxidase, biotin and other detection reagents.
Protein G Peroxidase Conjugate for ELISA and western blottingProtein G Biotin Conjugate for ELISA, western blotting and IHCProtein G conjugated to Dylight™ dyes for FLISA and immunofluorescence microscopyProtein G Fluorescein Conjugate for FLISA and immunofluorescence microscopyProtein G Alkaline Phosphatase Conjugate for ELISA
Rockland Protein A, Protein G and Protein A/G Sepharose™ is fast flow, low leakage affinity resins designed for high purity separation of monoclonal and polyclonal antibodies at the laboratory and process scales. Recombinant Protein A or Protein G or chimeric protein A/G are attached to sepharose resins via chemically-stable a mide bonds. Coupling chemistry that minimizes leakage of Protein A or Protein G ligands while preserve IgG-binding activity are utilized. The protein sepharose products show long term stability within pH range of 3 to 9 and short term stability within pH range of 2 to 10. For each lot, IgG-binding capacity is validated by human IgG binding assays to assure high quality of product. All Rockland Protein A and Protein G reagents undergo vigorous quality control to assure high performance quality.
Protein A Sepharose Conjugate for IgG purification (trial size)Protein A Sepharose Conjugate for IgG purificationProtein G Sepharose Conjugate for IgG purificationProtein A/G Sepharose Conjugate for IgG purification For antibodies to Protein A and Protein G
Agarose and Sepharose™ Conjugates
Sepharose™ is a trademark of GE Healthcare Inc.
Rockland Immunochemicals Inc.Limerick, PA 19468E-mail: email@example.comPhone: 800.656.7625