Scale‐Down: Simulating Large‐Scale Cultures in the Laboratory

Bioreactor scale-down is an efficient approach to evaluate the effects of the environment that cells will find at the large scale, through carefully designed laboratory-scale experiments. This chapter presents the general approach of bioreactor scale-down and discusses recent advances in the design of scale-down simulators as well as the effects in the cell factories that have been assessed in scale-down studies. A scaled-down model of a process is very often run side by side with the large-scale culture in order to better understand the large-scale process. Bioreactor scale-up is a complex task that takes into account information collected from the behavior of the cell at small scale and physical phenomena, such as transport processes and thermodynamics, which are interdependent parameters. The scale-down approach aims at mimicking conditions found in the large scale using laboratory-scale systems able to reproduce such conditions.