AMMONIA REMOVAL FROM MAMMALIAN-CELL CULTURE-MEDIUM BY ION-EXCHANGE MEMBRANES

Metabolites such as ammonia and lactic acid formed during mammalian ce ll culture can frequently be toxic to the cells themselves beyond a th reshold concentration of the metabolites. Cell culture conducted in th e presence of such accumulated metabolites is therefore limited in pro ductivity. This work demonstrates with laboratory data that a nonporou s ion-exchange membrane of the perfluorinated sulfonic acid type can b e used to contact the culture medium, and ammonia removed selectivity from the medium without disturbing the process. The technique of perva poration showed particular promise in this regard. The pervaporation u sed with inert gas sweep on the permeate side was found superior to th at used with vacuum application.