LAUSR

A simple method originally designed to control lactate accumulation in fed‐batch cultures of Chinese Hamster Ovary (CHO) cells has been modified and extended to allow cells in culture to control their own rate of perfusion to precisely deliver nutritional requirements. The method allows for very fast expansion of cells to high density while using a minimal volume of concentrated perfusion medium. When the short‐duration cell‐controlled perfusion is performed in the production bioreactor and is immediately followed by a conventional fed‐batch culture using highly concentrated feeds, the overall productivity of the culture is approximately doubled when compared with a highly optimized state‐of‐the‐art fed‐batch process. The technology was applied with near uniform success to five CHO cell processes producing five different humanized monoclonal antibodies. The increases in productivity were due to the increases in sustained viable cell densities. Biotechnol. Bioeng. 2017;114: 1438–1447. © 2017 Wiley Periodicals, Inc.