Factors affecting the production of foot-and-mouth disease virus in deep suspension cultures of BHK21 Clone 13 cells

Abstract
For maximum utilization of deep cultures to produce FMD virus it was important to have adequate control of culture temperature and pH. Culture temperature should be controlled within the range 34·25°7–35°C. and culture pH at 7·2. The culture system became less efficient as the cell concentration was increased from 1 × 106·0 to 9 × 106·0 cells/ml. A cell concentration of 2·5 × 106·0 cells/ml. represented a working compromise between efficiency and antigen titre/ml. for inactivated FMD vaccine production.The input virus/cell ratio had no effect on the time or titre of peak virus yield in the range 1:1 to 1:320. This makes the production of seed virus from small numbers of monolayer cultures feasible and economical.Virus yield was improved by the addition of 5% serum. It would be more satisfactory if a serum-free cell strain could be developed.