The modelling of protein expression as well as their purification are main research topics of the department of Bioprocess Engineering. These topics are often divided into the upstream production (USP) and downstream processing (DSP). At the interface, difficulties often arise, for example when highly effective proteins are difficult to purify and an economic production process cannot be established. In order to overcome these difficulties, we link the data from protein expression screening and process design from the start so that DSP requirements are considered during USP development and vice versa. The implemented models are constantly updated and improved based on new data collected with each experiment.