The preparation of 13C-15N-labeled nucleosides and methods for fractionating density-labeled RNA

✍ Scribed by Robert M. Grainger

• Publisher: Elsevier Science
• Year: 1976
• Tongue: English
• Weight: 818 KB
• Volume: 72
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1016/0003-2697(76)90561-3

✦ Synopsis

Chlorella pyrenoidosa can be grown in 90.8 atom% *"COP and 99. I atom% K15N0, to yield algae with substitution of 82 to 86% 'VI for 'YJ and 92 to 96% 15N for **N. Methods are described for extracting preparative amounts of ribonucleosides which can be used directly for density labeling RNA in eukaryotic cells. The separation of rSC-rSN-labeled from unlabeled RNA requires the high resolution of cesium formate equilibrium gradients. Banding of RNA in these gradients requires less than 48 hr of centrifugation and either formaldehyde or formamide will prevent RNA precipitation. The density increase of RNA isolated from 13C-15N-labeled Chlorella was found to be 2.7% in cesium formate gradients.