Studies on hybridoma cell growth and specific monoclonal antibody production rate

Abstract

Factors affecting hybridoma cell growth and specific monoclonal antibody (Mab) production rate was studied. Hybridoma Alps 25-3 was mouse-mouse hybridoma produced by somatic cell hybridization between myeloma sp 2/0 and spleen cell of Balb/c, and secreted IgGl against human Chorionic Gonadotropin (hcG) subunit. Reactor operation using bioreactor showed that specific growth rate, specific glucose consumption rate and specific ammonium ion production rate were nearly costant during 20-60 hr culture time. But only specific monoclonal antibody production rate was reduced in that period. These results suggested that secretion of Mab was inhibited by some factors and the factor might be Mab itself which had been secreted. When purified Mab from spent medium was added to cell culture broth, ELISA results showed inhibition upon secretion of Mab but SRID results didn``t show any inhibition Because SRID results were more accurate and reliable, it was true that secreted Mab idd not inhibit secretion of Mab. Toxic effect of ammonium ion on cell growth was shown at concentration of 7-10 mM $NH_3$-N, not at 3-4 mM that produced in batch culture. Therefore, ammonium ion was not major factor affecting cell density regulation. When spent medium was added to cell broth by 30\%, cell growth was not affected.