MEMBRANE-BASED PROCESS FOR THE REMOVAL OF TOXIC AMMONIUM ION PRODUCED DURING MAMMALIAN-CELL CULTURE

MAMMALIAN CELLS GROWN IN CULTURE EXCRETE AMMONIUM ION THAT ACCUMULATES IN QUANTITIES THAT MAY LIMIT CELL GROWTH AND REDUCE PRODUCT SYNTHESIS. THE USUAL TACTIC FOR LIMITING THE ACCUMULATION OF AMMONIA IS TO REPLACE THE "SPENT" MEDIUMWITH FRESH MEDIUM. SINCE MEDIUM REPLACEMENT INCREASES THE USE OF EXPENSIVE MEDIUM COMPONENTS, AMMONIUM ACCUMULATION LOWERS CELL AND PRODUCT YIELD ON MEDIUM AND INCREASES PRODUCTION COSTS. AN ATTRACTIVE STRATEGY FOR NULLIFYING THE PROBLEMS ASSOCIATED WITH AMMONIUM-ION EXCRETION IS TO PROVIDE A CONTINUOUS PROCESS FOR REMOVING AMMONIUM ION AND MAINTAINING IT AT A SUBINHIBITORY, STEADY-STATE CONCENTRATION. IN THIS PROPOSAL, WE DESCRIBE A MEMBRANE-BASED PROCESS FOR THE SELECTIVE AND CONTINUOUS REMOVAL OF AMMONIUM IONS PRODUCED DURING MAMMALIAN-CELL CULTURE. THE PROCESS PROMISES TO BE EFFECTIVE ON THE BASIS OF PRELIMINARY TECHNICAL AND ECONOMIC ANALYSES.