title: The preparation of 13C-15N-labeled nucleosides and methods for fractionating density-labeled RNA.
mesh_terms: D002247:Carbon Isotopes; D002499:Centrifugation, Density Gradient; D002708:Chlorella / Q000378:metabolism; D007553:Isotope Labeling; D008722:Methods; D009587:Nitrogen Isotopes; D009705:Nucleosides / Q000096:biosynthesis*; D012313:RNA / Q000096:biosynthesis / Q000302:isolation & purification*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D002247:Carbon Isotopes; D009587:Nitrogen Isotopes; D009705:Nucleosides; D012313:RNA