[The development of a purification method for Borna disease virus].

Borna disease virus represents an unknown neurotropic agent. It causes encephalitis in horses and sheep. The same or a similar type of virus might be responsible for psychiatric disorders in man. So far, it has been impossible to purify this agent to such an extent that it could be analyzed biochemically or electronmicroscopically. Therefore, different conventional virus purification techniques are applied in order to develop a method for obtaining purified Borna disease virus from infectious rat brain or persistently infected cell culture material.