Repligen Corporation develops bioprocessing technologies and systems used in the biological drug manufacturing process. Its products include Protein A ligands, cell culture growth factor products, chromatography products (OPUS pre-packed and smaller-scale columns), ELISA test kits, chromatography resins, filtration products (XCell and TangenX systems, KrosFlo systems, Spectra/Por products, and ProConnex fiber), and slope spectroscopy systems (under SoloVPE, FlowVPE, and FlowVPX brands). It collaborates with Navigo Proteins GmbH and sells its products to a variety of companies.