Effect of medium osmolarity on hybridoma growth, metabolism, and antibody production.

Osmolarity is an important process variable during the cultivation of mammalian cells in vitro. Cell culture medium is designed to have osmolarity in the range of 260 and 320 milliosmoles (mOsm), basically to mimic the osmolarity of serum at 290 mOsm/kg. Fragmented information on the response of hybridoma cells to elevated osmolarity is available. A decrease in cell growth and an increase in antibody production were reported at high o~molarit ies.~~ Influence of osmolarity on antibody productivity seems to be cell line dependent.12 Here we report the effects of osmolarity on hybridoma cell growth, metabolism, and antibody synthesis. The osmolarity of the medium was altered by the addition of both ionic and non-ionic substances.