Repligen Corp. provides advanced bioprocessing technologies and solutions used in the process of manufacturing biologic drugs. The firm serves through the following product lines: Chromatography; Filtration; and OEM Products (Proteins). The Chromatography product line includes a number 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 OEM products are represented by Protein A affinity ligands, which are a critical component of Protein A chromatography resins used in downstream purification, and cell culture growth factor products. The company was founded by Alexander G. Rich and Paul R. Schimmel in May 1981 and is headquartered in Waltham, MA.