Development of a chemically defined cultivation and transfection medium for HEK cell lines

Background In the process of generating a production cell, introduction of the gene of interest into the host cell can be performed by various physical, chemical or biological methods. Because of the greater scalability compared to physical methods and no safety concerns or restrictions that are associated with the use of viral systems, a transfection using chemical methods is of great interest. However, up to now up-scaling is limited by the challenge to transfect cells in conditioned media with the widely used reagent polyethylenimine (PEI). Considering the upscaling to gram yields, a culture medium that allows both, transfection and production is required. In this work, the current status in the development of such media supporting cell growth, transfection and protein production in HEK cells is presented. By this, processes will no longer be limited by media exchange prior transient transfection.