Abstract
The adaptation of 2 strains of West Nile virus, of Tamil Nad virus and of Japanese B encephalitis virus to chick embryo cell and monkey kidney cell cultures is described. After a variable number of passages, cytopathogenicity was sufficiently enhanced that tube cultures could be used for virus tit rations with all 3 viruses. Tissue-culture-adapted strains of West Nile virus could be studied by the plaque titration technique in bottle cultures of monkey kidney epithelial cells. This has not been possible so far with Japanese B virus. Neutralization tests with all 3 viruses were successfully performed in tube cultures and the plaque titration method was used for neutralization tests with 1 strain of West Nile. It is believed that the techniques used in these studies have potentialities as tools in epidemio-logical research in West Nile, Tamil Nad, and Japanese B encephalitis viruses and presumably other members of the arthropod-borne virus group.