[Patient with progressive multifocal leukoencephalopathy by in situ hybridization: comparison of in situ hybridization using isotopic and biotinylated probes].

Ward et al developed biotinylated probes to hasten virus nucleic acid detection. We used these probes to trace SV 40 and JC virus nucleic acids in PML brain. This procedure visualizes the hybridization of viral sequences by affinity cytochemistry with avidin-biotin peroxidase complexes and diaminobenzidine. In the PML frozen white matter numerous oligodendroglial nuclei hybridized with JC virus biotinylated and tritium labelled probes in areas adjacent to active demyelination. Although tritium labeled probes was most sensitive and gave lowest background this biotinylated method showed be useful as a rapid diagnostic test for the specific detection of viral nucleic acid sequences in brain tissues from patients with central nervous system (CNS) infectious diseases.