Protein A

Product               Protein A


Protein A is a surface protein found in cell wall produced by several strains of Staphylococcus aureus that consists of a single polypeptide chain and contains little or no carbohydrate.

Recombinant Protein A is produced in E. coli and shows essentially the same properties as native Protein A. 

Recombinant Protein A from E. coli is produced in validated fermentation and purification processes. In addition, no mammalian components are involved in either the fermentation or downstream processes. The purification process contains several chromatographic steps (but no affinity chromatographic step using human IgG).


Main areas of application  

Used as a ligand of antibody-purifying resins

Working Principle

Protein A molecule contains five high affinity binding sites capable of binding with the Fc region from IgG of many species of mammal including human and rabbit.

The interaction between Protein A and IgG is not equivalent for all species. Even within a species, Protein A interacts with some subclasses of IgG but not others. For example, human IgG1, IgG2 and IgG4 binds strongly, while IgG3 does not bind. There are also many examples in which monoclonal antibodies do not bind to Protein A, especially the majority of rat.



Purity                                      ≥ 95%

Production host                     Escherichia coli

Formulation                            20mM NaCl, 2mM TCEP, pH 7.0

Endotoxin                               < 5 EU/mg

Physical state                         Solution

Storage Temperature            ≤ -­20°C

Complies with ISO9001:2015 conditions