title: Double staining with crystal violet and methylene blue is appropriate for colonic endocytoscopy: an in vivo prospective pilot study.
abstract: OBJECTIVE
  Endocytoscopy (EC) at ultra-high magnification enables in vivo visualization of cellular atypia of gastrointestinal mucosae. Clear images are essential for precise diagnosis by EC. The aim of the present study was to evaluate the optimal staining method for EC in the colon.
  
  
  METHODS
  Thirty prospectively enrolled patients were allocated 1:1:1 to three distinct staining methods: 0.05% crystal violet (CV) alone, 1% methylene blue (MB) alone, or CV+MB (CM double). Normal rectal mucosae were stained with each dye and videos of EC images were recorded. Visibility of nuclei and gland formation after staining were evaluated as 'recognizable' or 'not recognizable'. Time for each parameter to become 'recognizable' was measured, and the average times for the three staining regimens were compared.
  
  
  RESULTS
  MB alone and CM double staining resulted in 'recognizable' (102 ± 27 vs 89 ± 22 s, P=0.263) nuclei within comparable periods of time, whereas CV alone was unable to identify nuclei. Gland formation became 'recognizable' sooner after CM double staining than after MB alone (61 ± 16 vs 108 ± 24 s, P<0.001).
  
  
  CONCLUSIONS
  Double staining with CV and MB, which rapidly provided recognizable images of both nuclei and gland formation, is an appropriate staining regimen for colonic EC.
authors.affiliation: Digestive Disease Center, Showa University Northern Yokohama Hospital, Yokohama, Japan.
authors.forename: Katsuro
authors.initials: K
authors.lastname: Ichimasa
authors.forename: Shin-ei
authors.initials: SE
authors.lastname: Kudo
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Mori
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Wakamura
authors.forename: Nobunao
authors.initials: N
authors.lastname: Ikehara
authors.forename: Makoto
authors.initials: M
authors.lastname: Kutsukawa
authors.forename: Kenichi
authors.initials: K
authors.lastname: Takeda
authors.forename: Masashi
authors.initials: M
authors.lastname: Misawa
authors.forename: Toyoki
authors.initials: T
authors.lastname: Kudo
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Miyachi
authors.forename: Fuyuhiko
authors.initials: F
authors.lastname: Yamamura
authors.forename: Shogo
authors.initials: S
authors.lastname: Ohkoshi
authors.forename: Shigeharu
authors.initials: S
authors.lastname: Hamatani
authors.forename: Haruhiro
authors.initials: H
authors.lastname: Inoue
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D003106:Colon / Q000473:pathology*; D003113:Colonoscopy / Q000379:methods*; D003581:Cytodiagnosis / Q000379:methods; D005260:Female; D005840:Gentian Violet / Q000494:pharmacology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007413:Intestinal Mucosa / Q000473:pathology; D007564:Japan; D008297:Male; D008751:Methylene Blue / Q000494:pharmacology*; D008875:Middle Aged; D010865:Pilot Projects; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013194:Staining and Labeling / Q000379:methods*
chemical_list: D005840:Gentian Violet; D008751:Methylene Blue
keywords: crystal violet; endocytoscopy; methylene blue; staining regimen; ultra-high magnification
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