title: Density labeling of proteins.
mesh_terms: D000596:Amino Acids; D002500:Centrifugation, Isopycnic; D003903:Deuterium; D004798:Enzymes / Q000096:biosynthesis*; D007553:Isotope Labeling / Q000379:methods*; D009587:Nitrogen Isotopes; D010103:Oxygen Isotopes; D011849:Radioactive Tracers; D014461:Ultracentrifugation
chemical_list: D000596:Amino Acids; D004798:Enzymes; D009587:Nitrogen Isotopes; D010103:Oxygen Isotopes; D011849:Radioactive Tracers; D003903:Deuterium