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

On-line, ''real-time'' monitoring of product concentration is important for mammalian cell culture fermentation. The continuous measurement of monoclonal antibodies allows for instantaneous determination of cell productivity and effective manipulation of the fermenter operating conditions for optimal production. This article will present the evaluation and application of a BioCad/RPM system (PerSeptive Biosystems) for rapid analysis of IgG concentration for hybridoma cell cultivation. Several commercial crossflow filtration devices are tested for low protein retention and fouling properties. A protein G column is used successfully for analyzing about 400 samples of IgG(1) without significant loss in separation efficiency. The ImmunoDetection system is integrated into a computer-controlled 15-L fermenter. This fermenter could be operated in batch and perfusion modes with cell densities up to 20 million cells/mL. A continuous cell-free sample stream obtained by a hollow fiber filter system is introduced to the BioCad/RPM for analysis. The speed of this system allows for real-time monitoring even at high densities with fast dynamics. A murine hybridoma cell (A10G10) is cultivated in batch and continuous reactors and antibody concentration is measured continuously with complete sterility. The results are compared to off-line measurements with good agreement. (C) 1995 John Wiley & Sons, inc.