In the preparation of antibody-enzyme conjugates there are a few advantages of using antibody fragments rather than intact antibodies. For example, antibody fragments lacking an Fc region have less interference with various Fc binding proteins, can easily penetrate cell membranes due to their lower molecule weight, and experience a lower nonspecific binding to cell surfaces. F(ab')₂ fragments are useful in immuno-histochemical studies.

• Chemistry:  Cleavage of IgG molecules below the disulfide groups in the hinge region using Pepsin to create a bivalent fragment and degraded smaller peptide fragments.
• Specification: Pure F(ab')₂.
• Procedure: After a buffer exchange (if necessary) digestion of IgG, in-process gel electrophoresis, purification and concentration determination.
• Price: Standard price covers labor and materials for the modification procedure, purification and testing.
• Starting materials: Please check biopolymer for ordering information.  
• Note: Due to the complexity of the digestion, differences of IgG subclasses and species of origin, extra charges may be added for some antibodies if additional procedures or test runs are deemed necessary.

References:

1. Rousseaux, J.; Biserte, G.; Bazin, H. The differential enzyme sensitivity of rat immunoglobulin G subclasses to papain and pepsin. Molecular Immunology 1980, 17, 469-482.
2. Coulter, A.; Harris, R. Simplified preparation of rabbit Fab fragments. J. Immun. Methods 1983, 59, 199-203.
3. Rousseaux, R.; Rousseaux-Prevost, R.; Bazin, H. Optimal conditions for the preparation of Fab and F(ab')₂ fragments from monoclonal IgG of different rat IgG subclasses. J. Immun. Methods 1983, 64, 141-146.