Automated immunochemical binding assay (flow-ELISA) based on repeated use of an antibody column placed in a flow-injection system.

A computer-controlled immunological binding assay intended for monitoring concentrations of interesting metabolites during bioprocesses has been developed. The main focus has been on speed, reliability, reproducibility and operational stability of the assay. The assay is based on the repeated use of a preparation of immobilized antibodies. Stability in the regeneration step is a prerequisite and was achieved by intermittent recalibration of the system. Furthermore, before immobilizing the polyclonal antibodies, they were purified on immobilized antigen and eluted using the same procedure as used in the assay cycle. Antibody preparation could be used for more than 50 cycles and in some cases for several hundred cycles. Since the calibration curve is valid for the whole life-time of the antibody column, recalibration only involved the registration of the column capacity. Experiments have been performed concerning monitoring of chromatographic separations as well as adsorption experiments from complex mixtures.