Repligen Corp. provides bioprocessing technologies and solutions used in the process of manufacturing biologic drugs. It serves through the following product lines: Chromatography, Filtration, Process Analytics, and Proteins. The Chromatography product includes a range of products used in the downstream purification and quality control of biological drugs. The Filtration products offer a number of advantages to manufacturers of biologic drugs at volumes that span from pilot studies to clinical and commercial-scale production. The Process Analytics products complement and support filtration, chromatography and proteins in-line absorbance measurements allowing for the determination of protein concentration in filtration, chromatography formulation and fill-finish applications. The Proteins product franchise is represented by Protein A affinity ligands, which are a critical component of Protein A chromatography resins used in downstream purification of virtually all mAb-based drugs on the market. The company was founded by Alexander G. Rich and Paul R. Schimmel in May 1981 and is headquartered in Waltham, MA.