Protein A
Protein A has high affinity to IgG from various species, for instance human, rabbit and guinea pig but only weak interaction with bovine and mouse. It binds with the Fc region of antibodies through interaction with the heavy chain. The Oncosimis® recombinant protein A consists of only 251 amino acids and has a predicted molecular mass of 28 kDa as estimated by SDS-PAGE.
The recombinant protein A is produced by expressing a modified protein A gene in E. coli. A specific purification process with strict quality control was taken to get the recombinant protein A with the purity of more than 98%. No human IgG affinity step is used during validated fermentation and purification and it is devoid of bacterial contaminants found normally in native Protein A.
Applications: Powerful affinity ligand for monoclonal antibody purification
Suitable for various immunochemical assays including WB, IHC, IP, and ELISA
Protein L
Protein L is different from protein A and protein G—Protein L binds predominantly to kappa light chains, without interfering with the antigen-binding site. Its interaction with Ig from various species varies. Protein L reacts strongly with human, baboon, guinea pig, mouse, rat, and pig IgG, and weakly with rabbit, horse, and goat IgG.
It may be used for the purification of IgG, IgM, IgA, IgE and IgD containing kappa light chains and for the purification of Fab and scFv fragments containing kappa light chains. It may be conjugated to a solid support for affinity purification or to marker molecules for detection. Protein L does not bind to bovine, sheep, or goat immunoglobulins.
Application:
Protein L has potential as a universal Ig ligand due to its interaction with the light chain. Its unique ability to bind kappa light chains makes it valuable in detection and purification of antibodies and antibody fragments.
Protein G
Protein G
Protein G has affinity for both Fab- and Fc-fragments of human IgG by independent and separate binding sites. Binding to the Fc region of immunoglobulins from several species by a non-immune mechanism exhibits greater affinity for almost all mammalian immunoglobulin G than Protein A.
Genetically engineered truncated protein G retains affinity for IgG but lacks albumin and Fab binding sites and membrane-binding regions. Protein G can bind all the human and mouse IgG subclasses. It can bind to both the fragment crystallizable (Fc) and antigen-binding fragment (Fab) components of the antibody.
Applications:
Protein G is a powerful reagent for the detection and purification of IgG and can be used in various immunochemical assays including WB, IHC, IP, and ELISA.
Protein A/G
Protein A/G binds to all subclasses of mouse IgG excluding mouse IgA, IgM, or serum albumin. This permits Protein A/G to be used in purification and detection of mouse monoclonal IgG antibodies, with no interference from IgA, IgM and serum albumin.
Streptavidin
Streptavidin is a tetrameric structure, composed of four monomer units which binds firmly to biotin. Each monomer subunit consists of eight twisted antithetical beta strands, forming tertiary barrel structures. It is widely used in molecular biology due to its unique high affinity for the vitamin biotin. The dissociation constant of the biotin-streptavidin complex is approximately ~10^-15 mol/L.
Streptavidin is widely used as a linker in biotechnology as it forms a very stable bond under well-preserved biological conditions. It exhibits a high binding affinity for biotin. This feature makes streptavidin a very efficient and versatile tool for novel sensor development. The streptavidin-biotin system is also used in detection, labeling, and drug delivery.
Application:
Streptavidin exhibits a strong affinity for biotin, forming a non-covalent yet robust interaction—ideal for WB, ELISA, and IHC detection systems.
| Sub Product | Details | Size | Price | |
| Protein A | View Details | -- | ||
| Protein L | View Details | -- | ||
| Protein G | View Details | -- | ||
| Protein A/G | View Details | -- | ||
| Streptavidin | View Details | -- | ||