Repligen (RepliGen in the company's logo) is an American company devoted to the development and production of materials used in the manufacture of biological drugs. The company is based in Waltham, Massachusetts, and incorporated in Delaware in 1981. A public company, Repligen is listed on the NASDAQ exchange under the symbol RGEN. As of February 2014, Repligen employed 116 people, about 50% of these based in Sweden.