Study on rt-PA production by recombinant CHO cells immobilized with a porous microcarrier

Using the porous microcarrier Cytopore, immobilized cultivation of a recombinant CHO cell line 4B3 producing tissue type plasminogen activator (rt-PA) was performed in a 3L stirring tank bioreactor with the perfusion of serum-free medium DF5S. 4B3 cells could enter the inner space and grow both in the inner space and on the surface of the Cytopore. The highest viable cell density of 4B3 and the highest production level of rt-PA were 8.83 x 10(6) cells/mL and 12,473 IU/mL, respectively. Purified by MPG adsorption chromatography and lysine-Sepharose 4B affinity chromatography, the purified rt-PA with a purity exceeding 98% was obtained from the culture supernatant.