COMPARISON OF SITE-SPECIFIC COUPLING CHEMISTRY FOR ANTIBODY IMMOBILIZATION ON DIFFERENT SOLID SUPPORTS

Silica is an important chromatographic support for high-performance affinity chromatography due to its high mechanical stability. However, silica is very different from traditional gel chromatographic materials, such as agarose, dextran, and polyacrylamide, with respect to many chemical and physical properties. Thus, it is expected that different immobilization techniques must be used for orienting the immobilized ligand on the surfaces of the two substrates. In this study, a site-specific coupling chemistry for immobilization of antibodies on modified silica surfaces and on agarose gels was investigated. The effects of substrates on the orientations of immobilized native and partially denatured antibodies was deduced. An important conclusion is that non-covalent interactions (physical adsorption) dominate the orientation of immobilized antibodies on silica surfaces.