Downstream processing (also known as DSP) refers to the recovery and purification of a product from natural sources, such as bacterial cells. Downstream processing is typically defined as the unit operations following the completion of cell growth and expansion. The purpose of downstream processing is to isolate, purify and concentrate the target products from the complex bulk matrix. Biopharmaceutical downstream processing is applicable in mAb or protein processes, as well as in the manufacture of oligonucleotides, polysaccharides and various vaccines. Downstream processing activities are performed at laboratory, pilot and manufacturing scale.