The deoxyribonucleic acid of Micrococcus radiodurans.
The DNA of Micrococcus radiodurans was prepared by three methods. Although the recovery of DNA varied considerably, the percentage molar base ratios of the DNA from the three preparations were essentially the same: guanine, 33+/-2; adenine, 18+/-1; cytosine, 33+/-2; thymine, 17+/-1. Base compositions calculated from T(m) values and from density in caesium chloride gradients also yielded guanine+cytosine contents of 66 and 68% of total bases respectively. No unusual bases were observed. The S(20,w) values were characteristic of high-molecular-weight DNA. Electron microscopy showed the purified DNA in long strands; occasionally these were coiled.
Schein
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Agricultural Research Council Virus Unit, Cambridge, and Department of Biochemistry, University of Vermont College of Medicine, Burlington, Vt., U.S.A.