Immunoaffinity antigen binding

Bomemann, C. et al., Fluorescence-labelled antigen-binding fragments (Fab) from monoclonal antibody 5F12 detect human erythropoietin in immunoaffinity capillary electrophoresis, Anal. Bioanal. Chem., 376,1074, 2003. 

Riordan, and M. Whitlow (1988). Single-chain antigen-binding proteins. Science 242 423-426. Blank, K., R Lindner, B. Diefenbach, and A. Pluckthun (2002). Self-immobilizing recombinant antibody fragments for immunoaffinity chromatography generic, parallel, and scalable protein purification. Protein Expr. Purif. 24 313-322. 

Immunoaffinity chromatography utilizes the high specificity of antigen—antibody interactions to achieve a separation. The procedure typically involves the binding, to a soHd phase, of a mouse monoclonal antibody which reacts either directly with the protein to be purified or with a closely associated protein which itself binds the product protein. The former approach has been appHed in the preparation of Factor VIII (43) and Factor IX (61) concentrates. The latter method has been used in the preparation of Factor VIII (42) by immobilization of a monoclonal antibody to von WiHebrand factor [109319-16-6] (62), a protein to which Factor VIII binds noncovalenfly. Further purification is necessary downstream of the immunoaffinity step to remove... 

Another potential disadvantage of an immunoaffinity separation is the assumed abundance of the purified antigen in sufficient quantities to immobilize on a chromatography support. Protein antigens should be immobilized at densities of at least 2-3 mg/ml of affinity gel to produce supports of acceptable capacity for binding antibody. Often, the antigen is too expensive or scarce to obtain in the amounts needed. 

Immunoaffinity chromatography makes use of immobilized antigen molecules to bind and separate specific antibody from a complex mixture. After the preparation of an... 

While the above-described sorbents are essentially nonspecific and designed to allow extraction of a wide range of analytes, there are also sorbent phases that are selective toward individual analytes, or at least classes of analytes. These are immunoaffinity (IA) sorbents and molecularly imprinted polymers (MIPs). In the first case, antibodies are immobilized on the solid support used for extraction, and the selective (in the ideal case specific) biochemical interactions allow an antigen to bind selectively to the antibody, whereas the other sample constituents are not retained and... 

Immunoaffinity chromatography can be used to purify protein antigens by immobilizing the relevant antibodies on an inert matrix such as polysaccharide beads. When exposed to a protein mixture, only the protein recognized by that antibody will bind to the beads and can be eluted later in pure or almost pure form. Cells bearing the antigen on their surface can also be purified using a similar procedure. 

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