Growth characterization of CHO DP-12 cell lines with different high passage histories

For industrial pharmaceutical protein production fast growing, high producing and robust cell lines are required. To select pH-shift permissive and faster growing sub-populations, the CHO DP-12 cell line was serially subcultured for more than four hundred days in shaker flasks. Initial adaptation to growth in suspension was carried out in chemically defined medium without hypoxanthine and thymidine (HT), while the final medium used for long term cultivation contains HT. Cell samples were cryopreserved at four different time points after 21, 95, 165 and 420 days. Cultivations of these four sub-populations (SP) in shaker flasks and bioreactors revealed considerable differences in specific growth rates and product formation as well as in the metabolism of glucose, lactate and several amino acids. For the elucidation of the intracelluar mechanism behind these alteration in growth characteristics and metabolism additional probes were analyzed using proteomic and metabolomic approaches [1].