Protein-Free Culture of Ras-Amplified Recombinant BHK-21 Cells

Abstract

A ras-amplified recombinant BHK-21 cell line (ras-rBHK-IgG), which hyperproduces recombinant human monoclonal antibody, was cultured in a protein-free medium. Protein-free medium for ras-rBHK-IgG cells was found to be superior to serum containing medium in terms of viability and recombinant antibody production. In particular, antibody, production in protein-free culture was shown to be five to ten limes higher than that in serum culture. However, when culturing cells at a high density in the hollow fiber bioreactor system, the enhancement of antibody production was not observed. On the other hand, rm-rBHK-IgG cells couldbe maintained for over a month in protein-free culture using the bioreactor system in contrast with serum culture which only lasted for a half month. The total amount of antibody obtained during cultivation was about two times greater in protein-free culture than in serum culture. Therefore, protein-free culture of ras-rBHK-IgG cells was demonstrated to be effective for middle scale production of recombinant human monoclonal antibody.