AFFINITY CAPILLARY-ELECTROPHORESIS - IMPORTANT APPLICATION AREAS AND SOME RECENT DEVELOPMENTS

Affinity capillary electrophoresis (ACE) is a broad term referring to the separation by capillary electrophoresis of substances that partici pate in specific or non-specific affinity interactions during electrop horesis. The interacting molecules can be found free in solution or ca n be immobilized to a solid support. Every ACE mode has advantages and disadvantages. Each can be used for a wide variety of applications. T his paper focuses on applications that include purification and concen tration of analytes present in diluted solutions or complex matrices, quantitation of analytes based on calibration curves, and estimation o f binding constants from direct and derived binding curves based on qu antitation of analytes or on analyte migration shifts. A more recent c hemicoaffinity strategy in capillary electrophoresis/capillary electro chromatography (CE/CEC) termed molecular imprinting ('plastic antibodi es') is discussed as well. Although most ACE studies are aimed at char acterizing small-molecular mass analytes such as drugs, hormones, and peptides, some efforts have been pursued to characterize larger biopol ymers including proteins, such as immunoglobulins. Examples of affinit y interactions that have been studied are antigen-antibody, hapten-ant ibody, lectin-sugar, drug-protein, and enzyme-substrate complexes usin g ultraviolet, laser-induced fluorescence, and mass spectrometer detec tors. This paper also addresses the critical issue of background elect rolyte selection and quantitation of analytes. Specific examples of bi oaffinity applications are presented, and the future of ACE in the bio medical field is discussed. (C) 1998 Published by Elsevier Science B.V .