Development of high density mammalian cell culture system for the production of tissue-type plasminogen activator

A high cell density culture system for the anchorage dependent CHO cells was developed based on the combination of in situ removal of ammonium ion and microcarrier culture system, and semi-fed-batch feeding of glucose and glutamine was employed to the developed culture system. The glass bead was selected as an optimum microcarrier in terms of cell growth. An ammonium ion selective zeolite, Phillipsite-Gismondine, was packed in a dialysis membrane and equipped on the agitator of spinner reactor for in situ removal of ammonium ion. The semi-fed-batch operation was employed to the novel culture system for the high density cell culture, and the results showed the cell growth was improved by 32% and tPA productivity by 250%.