Effects of Abrupt and Gradual Osmotic Stress on Antibody Production and Content in Hybridoma Cells That Differ in Production Kinetics

AB2‐143.2 cells exhibit non‐growth‐associated antibody production (constant specific antibody production rate (q_Ab) throughout batch culture), while IND1 cells exhibit growth‐associated production (decrease in q_Ab during stationary phase). AB2‐143.2 cells increase q_Ab following abrupt batch osmotic stress. Enhanced antibody production in IND1 cells after batch osmotic shock is evidenced as maintenance of the higher exponential phase QAb into the stationary phase. AB2‐143.2 cells also increase q_Ab in response to gradual osmotic stress in continuous culture. In contrast, IND1 cells decrease 9Ab during gradual osmotic stress. Although the two cell lines differ in antibody production, they have very similar intracellular antibody content profiles. Both show (1) constant antibody content during the exponential phase in control culture with a decrease as cells enter stationary phase; (2) maintenance of exponential‐phase antibody content into the stationary phase after batch osmotic shock; and (3) no change in antibody content in response to gradual osmotic stress.