A U.S. Patent for a “Method of Producing a Polypeptide or Virus of Interest in a Continuous Cell Culture” was awarded to Baxalta on March 5th, 2019. The present invention is a chemostat-like continuous cell culture system that combines certain advantages of perfusion open systems and chemostat open systems to improve the culturing of mammalian cells, e.g., genetically modified cells, particularly in serum-free or chemically-defined media. The continuous culture system described herein involves culturing mammalian cells in a continuous cell culture system, which comprises a cell retention device. Learn More