Detection of polyoma virus DNA in PML-brain tissue by (in situ) hybridization.

The human papova (JC) virus was extracted from brain of a patient with progressive multifocal leukoencephalopathy. A single band of virus was obtained at a density of 1.345 g/ml CsCl.JC virus DNA was purified and a highly specific cRNA was generated in vitro. In situ hybridization with JC virus cRNA and autoradiography on sections of the same brain revealed silver grains over oligodendrocytes, astrocytes and possible vascular endothelial cells, indicating the presence of JC virus DNA in these different cell classes.