title: Evaluation of lanthanide salts as alternative stains to uranyl acetate.
abstract: Uranyl acetate (UAc) has been generally used not only as a superb staining reagent for ultrathin sections of plastic-embedded biological materials, but also as high-contrast negative stains for biological macromolecules such as particles of protein or virus. However, the use and purchase of radioactive UAc have been restricted. In this study, we determine the performance of ytterbium triacetate, lutetium triacetate, samarium triacetate and gadolinium triacetate as new staining reagents for biological electron microscopy. We observed chemically fixed spinach (Spinacia oleracea) leaves stained with these reagents. Ultrathin sections were stained with these reagents. Some of them were counterstained with lead citrate. The transmission electron microscopy contrast of spinach organelles was evaluated in sections exposed to the conventional stain and new stains. We show acetate salts of samarium, gadolinium, ytterbium and lutetium could be excellent substitutes for UAc for thin section staining and for negative staining. In addition, each reagent showed appreciable negative-staining effects.
authors.affiliation: EM Application Department, EM Business Unit, JEOL Ltd, 3-1-2 Musashino Akishima, Tokyo 196-8556, Japan nhosogi@jeol.co.jp.
authors.forename: Naoki
authors.initials: N
authors.lastname: Hosogi
authors.affiliation: EM Application Department, EM Business Unit, JEOL Ltd, 3-1-2 Musashino Akishima, Tokyo 196-8556, Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Nishioka
authors.affiliation: Department of Pharmaceutical Sciences, Toho University, 2-2-1, Miyama, Funabashi, Chiba 274-8510, Japan.
authors.forename: Masamichi
authors.initials: M
authors.lastname: Nakakoshi
mesh_terms: D017122:Bacteriophage T4; D005682:Gadolinium / Q000737:chemistry; D006652:Histological Techniques; D028581:Lanthanoid Series Elements / Q000737:chemistry*; D008187:Lutetium / Q000737:chemistry; D046529:Microscopy, Electron, Transmission / Q000379:methods*; D008867:Microtomy / Q000379:methods; D016624:Negative Staining; D015388:Organelles; D009942:Organometallic Compounds / Q000737:chemistry; D012492:Salts; D012493:Samarium / Q000737:chemistry; D018724:Spinacia oleracea / Q000648:ultrastructure*; D013194:Staining and Labeling / Q000379:methods*; D015018:Ytterbium / Q000737:chemistry
chemical_list: D028581:Lanthanoid Series Elements; D009942:Organometallic Compounds; D012492:Salts; C005460:uranyl acetate; D012493:Samarium; D008187:Lutetium; D005682:Gadolinium; D015018:Ytterbium; C008261:lead acetate
keywords: gadolinium triacetate; lutetium triacetate; samarium triacetate; staining reagent; transmission electron microscopy; ytterbium triacetate