In-situ cell density monitoring and apoptosis detection in adherent Vero cell bioreactor cultures

Background In cell-based processes, and particularly in viral vaccine production, cell growth and death are strategic informations to obtain for process monitoring (ie. scale-up, determination of MOI, TOI, and harvest time). Dielectric spectroscopy is a tool which was increasingly implemented on cell-culture bioreactors as it presents great potentials, compared to other methods, for the in-line monitoring of these two crucial parameters. Considering viral vaccine production, Vero cells are one of the most employed cell platform. But, due to its adherent characteristics, few in-line techniques were developed for cell density monitoring, on the contrary to the ones available for suspension cells. In addition, it should be underline that no in-line technique exists for quantification or detection of the mammalian cell death, despite the importance of this parameter for cell culture processes.