Maximum quantity allowed is 999
Antibody-binding proteins such as protein A, protein G and protein L are bacterial proteins that bind specifically to antibodies. They are mainly used for antibody purification, immunoprecipitation (IP) and immunodetection. Each antibody binding protein exhibits different affinities to various animal species and antibody subtype. Therefore, it is important to determine the appropriate antibody-binding protein for your sample of interest. TCI has a wide variety of protein A, protein G and protein L conjugates for you to select from.
| Animal Species | Antibody Subtype | Protein A | Protein G | Protein L (*) |
|---|---|---|---|---|
| Human | IgG1 | ++ | ++ | ++ |
| IgG2 | ++ | ++ | ++ | |
| IgG3 | -- | ++ | ++ | |
| IgG4 | ++ | ++ | ++ | |
| IgM | - | -- | ++ | |
| IgD | -- | -- | ++ | |
| IgA | - | -- | ++ | |
| Mouse | IgG1 | ++ | ++ | ++ |
| IgG2a | ++ | ++ | ++ | |
| IgG2b | -- | ++ | ++ | |
| IgG3 | ++ | ++ | ++ | |
| IgM | - | -- | ++ | |
| Rat | IgG1 | - | + | ++ |
| IgG2a | -- | ++ | ++ | |
| IgG2b | -- | + | ++ | |
| IgG2c | ++ | ++ | ++ | |
| Goat | Total IgG | + | ++ | -- |
| Bovine | Total IgG | + | ++ | -- |
| Rabbit | Total IgG | ++ | ++ | - |
| Chicken | Total IgY | -- | -- | -- |
++: Strong; +: Medium; -: Low; --: None
* Protein L binding is restricted to antibodies that contain the right subtypes of κ light chains.
Protein A is a bacterial cell wall component from Staphylococcus aureus that specifically binds to the Fc region of IgG derived from various species including human, rabbit, mouse and cow. Our products consist of a recombinant protein A mutant which allows elution of antibodies under mild conditions (pH 4.0). As there is no change in antibody binding affinity, it can be used in the same way as normal protein A.
Protein A agarose in which protein A is bound to an agarose resin by a covalent coupling method can be used in antibody purification and immunoprecipitation. Antibody purification using protein A agarose usually requires an acidic buffer solution between pH 2.5 and pH 3.0 during elution steps. However, this frequently causes the antibody to undergo acid denaturation, changing its higher-order structure, resulting in antibody aggregation and inactivation. TCI’s protein A agarose uses a genetically modified protein A mutant which allows for the elution of antibodies under mild conditions (pH 4.0), under which most antibodies do not denature, as shown in Figure 1.
Protocol:
The majority of applied human IgG was successfully eluted at pH4.0 when using P2461.
Protein G is a bacterial cell wall component of Group G Streptococci strain. It binds specifically to the Fc region of immunoglobulins (especially IgG) and weakly to the Fab fragment.
Protocol:
Protein L is a cell wall molecule from the bacterial species Peptostreptococcus magnus. It binds immunoglobulin light chains in a wide range of species including human, mouse, rat, pig, and hamster, and can bind to any immunoglobulin isoform containing a kappa light chain (IgG, IgM, IgA, IgE, and IgD). It can also bind single-chain antibodies (scFv) and Fab fragments with κ light chains.
Protocol:
