Comparison of the biologic and biophysical properties of the progeny of intact and ether-extracted Rauscher leukemia viruses.

Abstract

The biologic and biophysical properties of intact and ethyl ether-extracted Rauscher leukemia virus were studied. Treatment of concentrated Rauscher mouse plasma virus with ether results in a rapid loss of infectivity, but the aqueous phase contains viral nucleoids which are still infectious. Bioassay of subpassaged progeny virus of mice inoculated intracranially with ether-extracted Rauscher virus revealed essentially the same leukemogenic response as that of intact virus. Centrifugation experiments on potassium tartrate gradients with 32P-labeled intact and ether-extracted tissue culture virus (JLS-V10) showed a shift in the radioactive peak from the 1.16 density of intact virus to a greater buoyant density of 1.28 with the nucleoids. Electron microscope examination of the high density material revealed only nonenveloped virus particles.