The effect of cellular growth, metabolism, and monoclonal antibody production on an industrial GS-NS0 cell line to hyper-osmotic medium was studied. The GS-NS0 cell line was found to have an optimum growth rate at a medium osmolality of 350 mosm/kg and an optimum specific productivity at 450 mosm/kg. Medium osmolality was shown to affect cell size as the cell line exhibited a regulatory cell volume increase response after an initial introduction into hyper-osmotic conditions.

The response of the cell line to an osmotic shift was also studied. Osmolality of the culture medium was increased, at two different time points, through the addition of NaCl. The shift in osmotic pressure was found to have a positive impact on specific productivity of the monoclonal antibody produced.

A finger print of the metabolic response of the GS-NS0 cell line to increased medium osmolality was determined. The application of metabolomics to mammalian cell cultures has not been widely explored. In this study, the cells were quenched and extracted using methods previously developed for microbial and plant cultures. An increase in concentration of internal amino acids, known to be osmolytes, was found under hyper-osmotic conditions.