SELECTING AND DESIGNING CELL-LINES FOR IMPROVED PHYSIOLOGICAL-CHARACTERISTICS

We have developed several approaches to create cell lines with improve d characteristics in cell culture. In some cases it has been possible to isolate natural variants with useful properties. Cholesterol indepe ndent variants of the mouse NSO myeloma cell line were isolated by clo ning in a selective medium. A glutamine independent variant of a hyrid oma was isolated by continuous (chemostat) culture under glutamine lim ited conditions in the presence of glutamate. Choline independent cell s were isolated from a choline limited chemostat. In an alternative ap proach to modifying cell behaviour, we have used recombinant DNA techn iques to introduce the glutamine synthetase (GS) gene to a hybridoma. This resulted in glutamine independence and increased productivity.