title: Method for restricting incorporation of radioactivity from  3 H-thymidine into deoxyribonucleic acid only during outgrowth of spores of Bacillus cereus T.
abstract: When heat-activated spores of Bacillus cereus T (thy(-)) were germinated and grown in medium containing (3)H-thymidine, a significant amount of radioactivity was incorporated into ribonucleic acid and deoxyribonucleic acid (DNA). A method was developed to restrict the incorporation of radioactivity from (3)H-thymidine into DNA only. This was accomplished by labeling the cells with (3)H-thymidine in the presence of 2 mg of 2-deoxyadenosine per ml, 250 mug each of uracil, cytosine, and guanosine per ml, and 500 mug of adenosine per ml. Under these conditions, 97% of the radioactivity incorporated into cold trichloroacetic acid-insoluble material was associated with DNA only. In the absence of these compounds, DNA contained only 72% of the total radioactivity incorporated into cold acid-insoluble material.
mesh_terms: D000225:Adenine; D001409:Bacillus cereus / Q000254:growth & development / Q000378:metabolism*; D001431:Bacteriological Techniques; D002701:Chloramphenicol / Q000494:pharmacology; D002854:Chromatography, Paper; D003596:Cytosine; D004269:DNA, Bacterial / Q000032:analysis / Q000096:biosynthesis* / Q000302:isolation & purification; D003839:Deoxyadenosines; D006151:Guanosine; D006868:Hydrolysis; D012329:RNA, Bacterial / Q000032:analysis / Q000096:biosynthesis / Q000302:isolation & purification; D012997:Solvents; D013170:Spores / Q000254:growth & development*; D013171:Spores, Bacterial / Q000254:growth & development / Q000378:metabolism; D013936:Thymidine / Q000378:metabolism*; D014238:Trichloroacetic Acid; D014316:Tritium / Q000378:metabolism*; D014498:Uracil
chemical_list: D004269:DNA, Bacterial; D003839:Deoxyadenosines; D012329:RNA, Bacterial; D012997:Solvents; D014316:Tritium; D006151:Guanosine; D014498:Uracil; D014238:Trichloroacetic Acid; D002701:Chloramphenicol; D003596:Cytosine; D000225:Adenine; D013936:Thymidine