Factors affecting the productivity of glass sphere propagators.

The productivity of glass sphere propagators was studied at the 1 litre scale. For the growth of BKH monolayer cells there was an optimum pH of 7.0, but no critical upper level of dissolved oxygen. By controlling the levels of pH and dissolved oxygen the incubation period was reduced from 96 to 72 hours. In standard beds of glass spheres cell distribution and growth were uniform, but not in experimental tall, thin substrate beds. This was corrected by dividing the test systems into 3 parts and incubating them in series. Additional cell growth was achieved in the standard propagators by a replenishing exhausted medium. Cell productivity was also increased by supplying extra culture medium. By this means the number of cells recovered was similar to that from the 10 litre propagator. Such data is discussed to evaluate the largest practical scale of glass sphere propagators.