title: Platinum blue as an alternative to uranyl acetate for staining in transmission electron microscopy.
abstract: This paper introduces an aqueous solution of platinum blue (Pt-blue) as an alternative to uranyl acetate (UA) for staining in transmission electron microscopy (TEM). Pt-blue was prepared from a reaction of cis-dichlorodiamine-platinum (II) (cis-platin) with thymidine. When Pt-blue was dried on a microgrid and observed by TEM it showed a uniform appearance with tiny particles less than 1 nm in diameter. The effect of Pt-blue as an electron stain was then examined not only for positive staining of conventional ultrathin resin sections and counterstaining of post-embedding immuno-electron microscopy but also for negative staining. In ultrathin sections of the rat liver and renal glomerulus, Pt-blue provided good contrast images, especially in double staining combined with a lead stain (Pb). Almost all cell organelles were clearly observed with high contrast in these sections. Glycogen granules in the hepatic parenchymal cells were particularly electron dense in Pt-blue stained sections compared with those treated with UA. In longitudinal and transverse sections of budding influenza A viruses, a specific arrangement of rod-like structures, which correspond to the ribonucleoprotein complexes, was clearly shown in each virion stained with Pt-blue and Pb. When post-embedding immunoelectron microscopy was performed in ultrathin sections of HeLa cells embedded in Lowicryl K4M, the localization of Ki-67 protein was sufficiently detected even after Pt-blue and Pb staining. The present study also revealed that Pt-blue could be used for the negative staining of E. coli, allowing the visualization of a flagellum. These findings indicate that Pt-blue is a useful, safe, and easily obtainable electron stain that is an alternative to UA for TEM preparations.
authors.affiliation: Division of Genome Morphology, Department of Functional, Morphological and Regulatory Science, Faculty of Medicine, Tottori University, Yonago, Japan. sumire@grape.med.tottori-u.ac.jp
authors.forename: Sumire
authors.initials: S
authors.lastname: Inaga
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Katsumoto
authors.forename: Keiichi
authors.initials: K
authors.lastname: Tanaka
authors.forename: Toshio
authors.initials: T
authors.lastname: Kameie
authors.forename: Hironobu
authors.initials: H
authors.lastname: Nakane
authors.forename: Tomonori
authors.initials: T
authors.lastname: Naguro
mesh_terms: D000180:Acrylic Resins; D000818:Animals; D004847:Epithelial Cells / Q000378:metabolism / Q000648:ultrastructure; D004853:Epoxy Resins; D004926:Escherichia coli / Q000378:metabolism / Q000648:ultrastructure; D005407:Flagella / Q000378:metabolism / Q000648:ultrastructure; D006003:Glycogen / Q000378:metabolism / Q000648:ultrastructure; D006367:HeLa Cells; D006801:Humans; D009980:Influenza A virus / Q000378:metabolism / Q000648:ultrastructure; D019394:Ki-67 Antigen / Q000378:metabolism / Q000648:ultrastructure; D007678:Kidney Glomerulus / Q000378:metabolism / Q000648:ultrastructure; D008099:Liver / Q000378:metabolism / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission / Q000379:methods*; D008867:Microtomy / Q000379:methods; D015388:Organelles / Q000378:metabolism / Q000648:ultrastructure; D009942:Organometallic Compounds; D010316:Particle Size; D010984:Platinum; D051381:Rats; D013194:Staining and Labeling / Q000379:methods*; D016610:Tissue Embedding; D014771:Virion / Q000378:metabolism / Q000648:ultrastructure
chemical_list: D000180:Acrylic Resins; D004853:Epoxy Resins; D019394:Ki-67 Antigen; D009942:Organometallic Compounds; C005460:uranyl acetate; D010984:Platinum; C004875:EPON; C037883:Lowicryl 4KM resin; D006003:Glycogen