The purification of therapeutic proteins is an essential task in the production of biopharmaceuticals, which are drugs made from biological sources. This process involves the separation of the desired protein from impurities and contaminants, to ensure its safety and efficacy. Synonyms for purification of therapeutic proteins include protein fractionation, protein isolation, protein separation, and protein purification. Other related terms include bioprocessing, biomanufacturing, and downstream processing, which refer to the overall production process of these drugs. The use of advanced technologies, such as chromatography and filtration, has greatly improved the efficiency and quality of protein purification, making it a critical step in the biopharmaceutical industry.