Repligen Corporation is a bioprocessing company headquartered in Waltham, Massachusetts that provides products and services to the biopharmaceutical industry. The company's products are used in the production of monoclonal antibodies, recombinant proteins, and vaccines. Repligen's product portfolio includes chromatography products, filtration products, and protein A ligands. The company also provides bioprocess services, including process development and optimization, analytical testing, and protein characterization. Repligen was founded in 1981 and has grown through a combination of organic growth and acquisitions.