title: Imaging of chromosomes at nano-meter scale resolution using scanning near-field optical/atomic force microscopy.
abstract: Topographic and fluorescent images of whole barley chromosomes stained with YOYO-1 were observed simultaneously by scanning near-field optical/ atomic force microscopy (SNOM/AFM). The chromosome was relatively smooth and flat in the topographic images and no significant difference in height was present between regions of high fluorescent and low fluorescent intensity in the chromosomes. The telomeric region, labeled by fluorescence in situ hybridization (FISH) method, was also observed by SNOM/AFM at high resolution, and fluorescent signals of the telomeric region were clearly defined on the topographic image of chromatin fibers on the chromosome at the nano-meter scale level. Although the telomeric signals were usually visualized as a single fluorescent region at the end of sister chromatids by conventional light microscopy, they were observed separately as two fluorescent regions, less than 100-200 nm distance, using the SNOM/AFM. The SNOM/AFM offers great potential in identifying particular single gene location on chromosomes in the near future.
authors.affiliation: National Food Research Institute, Tsukuba, Ibaraki, Japan. ohtani@affrc.go.jp
authors.forename: Toshio
authors.initials: T
authors.lastname: Ohtani
authors.forename: Motoharu
authors.initials: M
authors.lastname: Shichirii
authors.forename: Daisuke
authors.initials: D
authors.lastname: Fukushi
authors.forename: Shigeru
authors.initials: S
authors.lastname: Sugiyama
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Yoshino
authors.forename: Toshiro
authors.initials: T
authors.lastname: Kobori
authors.forename: Shoji
authors.initials: S
authors.lastname: Hagiwara
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Ushiki
mesh_terms: D001583:Benzoxazoles; D002871:Chromosome Banding; D032461:Chromosomes, Plant / Q000648:ultrastructure*; D005456:Fluorescent Dyes; D001467:Hordeum / Q000235:genetics; D017404:In Situ Hybridization, Fluorescence / Q000379:methods; D018625:Microscopy, Atomic Force / Q000379:methods*; D036103:Nanotechnology / Q000379:methods*; D011806:Quinolinium Compounds; D016615:Telomere / Q000648:ultrastructure
chemical_list: D001583:Benzoxazoles; D005456:Fluorescent Dyes; D011806:Quinolinium Compounds; C075296:1,1'-((4,4,7,7-tetramethyl)-4,7-diazaundecamethylene)bis-4-(3-methyl-2,3-dihydro(benzo-1,3-oxazole)-2-methylidene)quinolinium