Amyotrophic lateral sclerosis: search for poliovirus by nucleic acid hybridization.

Radioactive-labeled complementary DNA (cDNA) probes specific for either poliovirus type I or type II were hybridized with cellular RNA from the brains of patients dying of amyotrophic lateral sclerosis. In 11 brains examined, the percentage of hybridization for either polio type was the same as the percentage in normal brains. Although hybridization is a sensitive method for detection of viral genome material in infected cells, inability to detect viral nucleic acid by current techniques does not preclude the presence of viral genetic material in the tissue examined.