Abstract: This invention provides a process for large-scale purification of living Japanese encephalitis virus (JEV) suitable for use in vaccine preparation from a JEV source, including a JEV-infected cell culture and a JEV-infected mouse brain. The process includes the following steps: (a) obtaining a sample from a JEV-infected mouse brain or a JEV-infected cell culture, (b) subjecting the sample to a preliminary separation to remove cell and cell debris from the sample of step (a), (c) concentrating the sample from step (b) by ultra-filtration to remove substances having molecular weight below 100 kDa, and (d) subjecting the sample concentrate to gel filtration to obtain a substantially pure fraction of JEV.

Abstract: An apparatus for cultivating cells as disclosed includes a cell culture chamber having inlet and outlet ports, a substrate (7) with an anchorage surface for attachment of cells, and a system for circulating a culture medium in the cell culture chamber through the inlet and outlet ports. The medium circulating system cooperates with valves to control the surface level of the medium in order to submerge the anchorage surface in the culture medium and intermittently expose the substrate from the culture medium, thereby increasing the rate of gas exchange through a thin film of the culture medium formed on the anchorage surface. A method for cultivating cells by using the apparatus is also disclosed.