title: Differential diagnosis of variola viruses by microfocus assay.
abstract: Variola virus was identified by means of a method involving the formation of microfoci on microplate cultures of HeLa cells. It was possible to distinguish between variola major and variola minor viruses within 48 h of receipt of the specimens by determining the temperature sensitivity of focus formation.
mesh_terms: D001431:Bacteriological Techniques; D002478:Cells, Cultured; D003937:Diagnosis, Differential; D006367:HeLa Cells; D006801:Humans; D012899:Smallpox / Q000175:diagnosis*; D013696:Temperature; D012901:Variola virus / Q000302:isolation & purification*; D014776:Virus Cultivation