Recombinant technology plays in important role in developing protein therapeutics. Many companies offer services to clone and express recombinant DNA. Typical expression systems include Yeast, E. Coli, Baculovirus, Insect Cells or Mammalian Cells. Some companies offer the expressed recombinant protein in stable cells lines or they can purify the proteins using various chromatography techniques, including Ion-Exchange and Affinity Chromatography. When it comes time to produce the manufactured proteins or antibodies, companies can offer small-scale production that can be scaled-up, or some companies offer large-scale fermentation facilities to commercially produce protein therapeutics.