Most of the active components in drugs either are compounds obtained by chemical synthesis or biomolecules produced by microorganisms (often proteins), which are then called biopharmaceuticals. When we talk about biomolecule production it can be separated into two sections: the up- and downstream-process. The main focus of an upstream-process lies on the preparation of the host cells and their fermentation. After a successful production the target protein needs to be separated from impurities. Protein purification – the downstream process – is an important procedure used to produce biomolecules in a highly pure form for the use in human healthcare.