中国生物工程杂志

Using the character of natural aggregation of CHO cells, and an ultrasonic and sedimentation column combined perfusion system to promote cells aggregation and retention into bioreactor, we cultured successfully recombinant CHO cell strain MK3-A2, which could secrete TNK-tPA, by a serum-free perfusion culture system. The culture periods in our two experiments were as long as 77 and 110 days respectively. The cells density reached 2×107 cells /ml. The average volumetric productivity of TNK-tPA was 89 mg/L.d, and the highest one was 216mg/L.d.The cells aggregation rate was approximately 90%, and the diameters of most of them were 285～570μm. During the perfusion culture the cells retention rate almost kept in 95% and the viability of cells was more than 85%.Thus, it means that aggregation culture with such perfusion system could be used to scale up produce biopharmaceuticals instead of microcarrier culture system.