Fast FIA-immunoanalysis systems for the monitoring of downstream processes

The use of a flow-injection analysis system (FIA) with an integrated heterogeneous immuno assay was tested for the on-line detection in biotechnological downstream processes. This paper describes the application of immobilised antibodies of recombinant antithrombin III (r-AT III) and recombinant tissue-type plasminogen activator (rt-PA) in a gelfiltration-process of simulated mammalian cell cultivation supernatant. The automated assay was found to be able to detect the corresponding fractions of the target protein. Furthermore, it can also give information about the purity of the collected fractions which could be achieved under the selected conditions.