Infectious ribonucleic acids derived from mouse brains infected with two kinds of arbor virus group B.

Abstract

INFECTIOUS ribonucleic acid (RNA) has been extracted by phenol treatment1 from cells infected with animal viruses. In Group B of the arbor viruses, it has been recently reported that the RNA extracted from mouse brain infected with Murrary Valley encephalitis virus2 or Japanese B virus3 and from Ehrlich ascites tumour cells infected with West Nile encephalitis4 are infectious. The purpose of this present communication is to add a datum concerning the extraction of infectious RNA from mouse brains infected with dengue fever virus to the reports of viral RNA already published, and to compare the effects of cold- and hot-phenol extractions on the yields of infectious RNA from the cells infected with Japanese B encephalitis virus and dengue fever virus, respectively.