Infectious but non-leukemogenic Friend leukemia virus obtained after prolonged cultivation in vitro.
D000818:Animals; D002460:Cell Line; D046508:Culture Techniques; D005622:Friend murine leukemia virus / Q000254:growth & development* / Q000472:pathogenicity; D051379:Mice; D008979:Moloney murine leukemia virus / Q000472:pathogenicity; D014762:Viral Interference; D014776:Virus Cultivation