[Cellular fusion induced in vitro by the mouse scrapie agent]

A method is described to demonstrate and measure the cell-fusion in vitro induced by viruses. This technique has been established using Sendai virus. It has been used to study the fusing ability of the Scrapie agent which is responsible of a slowly progressing spongiform encephalopathy in Mice. In Vero cells, the Scrapie agent induces a fusion which appears slowly and remains moderate. This test can help to detect the human spongiform encephalopathies.