New developments in the cultivation of hybridoma cells in homogeneous continuous perfusion systems.

Monoclonal antibodies (MCA) are of great value both for in vitro and in vivo diagnostic and for therapeutic application. For in vitro application relatively small amounts of antibody are required. The therapeutic application, however, requires larger quantities. For this reason different cultivation systems have been developed in the past years. In our laboratory the continuous perfusion system in routinely applied for the cultivation of hybridoma cells. Cell and product yields obtained in this homogeneous cultivation system will be described and data of the monitoring of environmental conditions as nutrients and metabolites will be presented. To obtain information on the stability of expression a spot-ELISA assay was developed to determine the ratio of producers to non producers and the incidence of switch variants. Flow cytometry was applied for analysis of the cell cycle and to follow the course of cytoplasmic and surface IgG expression. These and other test systems provide information about the stability of production of monoclonal antibodies by hybridoma cells in continuous perfusion systems.