When digesting an IgG that does not bind to Protein A, how do I purify the Fab and F(ab´)2 fragments?
If the IgG is a species or subclass that does not bind to Protein A, researchers can immobilize an antibody specific for the desired fragment. For example, to purify digested rat IgG2a, use the Aminolink Plus Immobilization Kit (#44894) to immobilize goat anti-rat Fc antibody. Our Tech Tip #34 and other web resources list IgG binding properties of Protein A. (Because Protein G and Protein A/G bind Fab fragments, they are not effective for this application.
