REAL-TIME MONITORING OF PROTEIN SECRETION IN MAMMALIAN-CELL FERMENTATION - MEASUREMENT OF MONOCLONAL-ANTIBODIES USING A COMPUTER-CONTROLLEDHPLC SYSTEM (BIOCAD RPM)/

On-line, ''real-time'' monitoring of product concentration is importan t for mammalian cell culture fermentation. The continuous measurement of monoclonal antibodies allows for instantaneous determination of cel l productivity and effective manipulation of the fermenter operating c onditions for optimal production. This article will present the evalua tion and application of a BioCad/RPM system (PerSeptive Biosystems) fo r rapid analysis of IgG concentration for hybridoma cell cultivation. Several commercial crossflow filtration devices are tested for low pro tein retention and fouling properties. A protein G column is used succ essfully for analyzing about 400 samples of IgG(1) without significant loss in separation efficiency. The ImmunoDetection system is integrat ed into a computer-controlled 15-L fermenter. This fermenter could be operated in batch and perfusion modes with cell densities up to 20 mil lion cells/mL. A continuous cell-free sample stream obtained by a holl ow fiber filter system is introduced to the BioCad/RPM for analysis. T he speed of this system allows for real-time monitoring even at high d ensities with fast dynamics. A murine hybridoma cell (A10G10) is culti vated in batch and continuous reactors and antibody concentration is m easured continuously with complete sterility. The results are compared to off-line measurements with good agreement. (C) 1995 John Wiley & S ons, inc.