Newly Synthesized DNA and Bacillus subtilis DNA Incorporated into Transformable Diplococcus pneumoniae

Summary

Both ³H-thymidine and small ³²P-labeled elements of heavy density ³²P²H ¹⁵N-Bacillus subtilis 168⁺ DNA were covalently incorporated into macromolecular DNA of genetically transformable R1 Diplococcus pneumoniae. The ³H and ³²P markers in the DNA extracted from D. pneumoniae both assumed the position of light density doublestranded DNA on CsCl isopycnic equilibrium centrifugation when the DNA was untreated or shortened by sonication prior to centrifugal analysis, and of light density single-stranded DNA when first denatured by heat.