HBs-MAb production in perfusion culture with selective ammonia removal system

Conventional serum-free perfusion cultures of hybridoma TO-405 cells using medium supplemented with additional amounts of glucose, glutamine, beta-mercaptoethanol and growth factors failed to yield cell densities and monoclonal antibody (MAb) concentrations which were significantly different from the results of unsupplemented perfusion cultures. Ammonia building-up to inhibitory concentrations in all the cultures was regarded as one of the primary reasons. When perfusion cultures and medium supplementation were done coupled to the ammonia removing system, the viable cell density grew to a maximum of 2.5 x 10(7) cells per ml at high percentage viability. This value is more than a 300% increase from that of conventional perfusion cultures and better compared to serum-supplemented cultures. The monoclonal antibody accumulated to a concentration as high as 26.3 x 10(5) mIU per ml. This is about 10-times when compared to that which can be achieved in ordinary perfusion cultures.