Fortschritte in der immunchemischen Analytik von gewässerrelevanten Schadstoffen

Up to now, immunoassays play a major role among immunochemical methods for water analysis. Further developments are focussed at the reduction of time required for analysis, automation, and multianalyte approaches. Important progress has been achieved in flow injection immunoanalysis, immunosensing, and array technologies. The advantages of these methodologies are mainly seen in those applications, which keep the efforts for sample preparation to a minimum. In spite of the achieved progress, especially with respect to assay sensitivities, the availability of suitable antibodies is still considered the limiting factor for the application of immunochemical methods in water analysis. The hybridoma technology has provided the basis for the production of unlimited amounts of monoclonal antibodies, i.e., homogeneous antibody preparations of unchanging quality. However, the production of new monoclonal antibodies still requires new immunisations and new animals. Only recombinant technologies offer the potential not only for inexpensive mass production, but also for the alteration of given antibody properties at the DNA level. The immune system with its possibilities for affinity maturation and diversification of antibodies is used as a model for the production of new or improved antibody properties. Antibody libraries, which represent the immune repertoire in vitro, provide the basis for the selection of suitable variants and further optimisation in subsequent diversification and selection steps. Examples are given for immunoassays with recombinant fusion proteins and Fabs for the analysis of herbizides in water.