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Protein A and Protein G Reagents


Protein A and Protein G Reagent Overview


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

 

Dot blot of human (1), Golden Syrian Hamster (2) and sheep (3) IgG using HRP Protein A conjugate

 

SEPHAROSE™ Protein A

 

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 and Conjugates

 

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.  

 

Protein A

 

 

Protein A and Conjugates

 

 

 

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 microscopy
Protein A Fluorescein Conjugate for FLISA and immunofluorescence microscopy
Protein A Alkaline Phosphatase Conjugate for ELISA

 


Protein G and Conjugates

 

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

 

Protein G and Conjugates

 

Protein G Immunoglobulin Detection Applications


Protein G Peroxidase Conjugate for ELISA and western blotting
Protein G Biotin Conjugate for ELISA, western blotting and IHC
Protein G conjugated to Dylight™ dyes for FLISA and immunofluorescence microscopy
Protein G Fluorescein Conjugate for FLISA and immunofluorescence microscopy
Protein G Alkaline Phosphatase Conjugate for ELISA

 


Protein A and Protein G Sepharose™

 

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 AG Sepharose Conjugates

 

 

Protein A and Protein G

 

 

 

  

Immunoglobulin Purification Applications


Protein A Sepharose Conjugate for IgG purification (trial size)
Protein A Sepharose Conjugate for IgG purification
Protein G Sepharose Conjugate for IgG purification
Protein A/G Sepharose Conjugate for IgG purification

 For antibodies to Protein A and Protein G

Sepharose™ is a trademark of GE Healthcare Inc.

 

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