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Microtiter plates are a common tool for clone selection in biopharmaceutical development. A way of visualizing and evaluating these systems and key processes parameters is the application of Computational Fluid Dynamics (CFD). CFD is a powerful tool for the modelling of hydrodynamics and mass transfer parameters. In this work, CFD was used to determine the specific surface area, the volumetric power input and the oxygen mass transfer coefficient kLa for two different microtiter plates with different scales (100 μL ‐ 5 mL). For this purpose, a new method of predicting the kLa is presented and calibrated with literature data. Scaling effects in shaken microtiter plates are evaluated by comparing two culture volume scales under various operating conditions. To test validity of these models, three different Boehringer Ingelheim Pharma proprietary CHO production cell lines with different growth characteristics were cultivated using the respective microtiter plates under different conditions until limitations in growth and viability were observable. The cell culture data then was compared to different parameters obtained by CFD. The calculated kLa values match the cell culture performance in the 96‐deepwell by predicting lowered oxygen transfer with increasing culture volume and decreasing orbital velocity. The same cells behave differently in the 6‐deepwell scale. Here, the overall larger shear stress might cause physical stress for the cells. The kLa model predicts overall higher shear rates for this system, supporting the experimental findings. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 2018

Despite the fact that aerated stirred tank reactors are widely used in industry and often studied, their design and scale‐up still remains challenging. Especially the specific power input is a crucial and geometry‐dependent scale‐up parameter, usually calculated with the dimensionless power number Po. Within the scope of this study, the power number is measured for different stirrer types and configurations in a laboratory and an industrial‐scale aerated stirred tank reactor. Good agreements to literature are found for the unaerated case for the two‐stage stirrer configurations at different stirrer spacing for both scales. By literature only the aerated case in the laboratory scale can be predicted. Scale‐up of an aerated industrial‐scale reactor is challenging because of a specific influence of the aeration. In case of a three‐stage Rushton configuration, an asymmetrical distribution of the stirrers should be preferred to ensure a high power number as well as good power performance under aerated conditions.