Criteria for bioreactor comparison and operation standardisation during process development for mammalian cell culture

Background Development of bioprocesses for animal cells has to deal with different bioreactor types and scales. Bioreactors might be intended for generation of cell inoculum and production, research, process development, validation or transfer purposes. During these activities, not only the difficulty of upand downscaling might lead to failure of consistency in cell growth, but also the use of different bioreactor geometries and operation conditions. In such cases, the criteria for bioreactor design and process transfer should be carefully evaluated in order to avoid an erroneous transfer of cultivation parameters. In this work, power input, mixing time, impeller tip speed, and Reynolds number have been compared systematically for the cultivation of the human cell line AGE1.HN within three partner laboratories using five different bioreactor systems. A common process window for mixing time in the range of 8 – 13 s has been found in bioreactors having significant differences in their inner geometries. The obtained results are employed for process standardisation and transfer between research institutions.