Parallel CHO-S cultivation in stirred tank bioreactors

[cculture]

Has anyone had experienced of parallel cho cultivations in benchtop scale stirred tank bioreactors? If every vessel (e.g. 4 to 8) share equal environmental conditions (T, pH, DO) how parallel cell density results could be achieved?

Let say if standard deviation of cell density is about 15% would this be acceptable when screening different environmental conditions. Of source there is some error in manual calculation of cells that can be included in 15%.