Measurement of antigen-antibody interactions with biosensors.

The introduction in 1990 of a new biosensor technology based on surface plasmon resonance has revolutionized the measurement of antigen-antibody binding interactions. In this technique, one of the interacting partners is immobilized on a sensor chip and the binding of the other is followed by the increase in refractive index caused by the mass of bound species. The following immunochemical applications of this new technology will be described: (1) functional mapping of epitopes and paratopes by mutagenesis; (2) analysis of the thermodynamic parameters of the interaction; (3) measurement of the concentration of biologically active molecules; (4) selection of diagnostic probes.