Separation of DNA Sequences Complementary to the RNA of Avian Myeloblastosis Virus from Chicken DNA by Alkaline Cesium Chloride Density Sedimentation

Density gradient sedimentation in alkaline cesium chloride of DNA from normal chicken embryos or leukemic myeloblasts fragmented to a size of 13Srevealed that the DNA sequences complementary to 70Savian myeloblastosis virus RNA sedimented in the high guanine plus cytosine region ahead of the main peak of cellular DNA. When the DNA was fragmented into pieces of 6.6Sthere was a broader distribution of the DNA sequences complementary to the viral RNA. This technique could be employed as a step towards the isolation of DNA copies of the entire viral RNA genome from the mass of host cellular DNA.