title: A new infrared fluorescent-labeling agent and labeled antibody for diagnosing microcancers.
abstract: OBJECTIVE
  We have developed infrared fluorescent labeling agents and infrared-ray fluorescence endoscopes to establish a novel diagnostic technique. Since the fluorescence intensity of the initial labeled antibody (ICG-sulfo-OSu-labeled antibody) was not sufficient for practical use, we synthesized indocyanine green acylthiazolidinethione (ICG-ATT), which was expected to label various target molecules having amino groups efficiently.
  
  
  METHODS
  To confirm imaging of infrared fluorescence intensity of ICG-ATT- and ICG-sulfo-OSu-labeled anti-MUC1 antibodies, cotton thread was soaked in various concentrations of the antibody solution in 0.1M PBS, and observed under the epi-illumination infrared fluorescence microscope. Localization and the intensity of infrared fluorescence and DAB coloring was compared in paraffin sections of human gastric mucosa.
  
  
  RESULTS
  In the study of cotton threads, both labeled antibodies showed relatively clear infrared fluorescence, and significant difference was not observed between the two antibodies. ICG-ATT-labeled anti-MUC1 antibody produced stronger staining than that by ICG-sulfo-OSu-labeled antibody. Localization pattern of infrared fluorescent staining was in good agreement with that by the conventional method with oxidized DAB staining.
  
  
  CONCLUSIONS
  ICG-ATT is useful as a fluorescent-labeling agent for diagnosis of microcancers by infrared fluorescence endoscopes.
authors.affiliation: Department of Digestive and Cardiovascular Medicine, The University of Tokushima School of Medicine, 3-18-15 Kuramoto-cho, Tokushima City 770-8503, Japan.
authors.forename: Masaya
authors.initials: M
authors.lastname: Tadatsu
authors.forename: Susumu
authors.initials: S
authors.lastname: Ito
authors.forename: Naoki
authors.initials: N
authors.lastname: Muguruma
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kusaka
authors.forename: Kumi
authors.initials: K
authors.lastname: Inayama
authors.forename: Terumi
authors.initials: T
authors.lastname: Bando
authors.forename: Yoko
authors.initials: Y
authors.lastname: Tadatsu
authors.forename: Koichi
authors.initials: K
authors.lastname: Okamoto
authors.forename: Kunio
authors.initials: K
authors.lastname: Ii
authors.forename: Yoshimitsu
authors.initials: Y
authors.lastname: Nagao
authors.forename: Shigeki
authors.initials: S
authors.lastname: Sano
authors.forename: Hiromi
authors.initials: H
authors.lastname: Taue
mesh_terms: D005753:Gastric Mucosa / Q000737:chemistry; D006801:Humans; D007208:Indocyanine Green / Q000032:analysis*; D008856:Microscopy, Fluorescence / Q000379:methods; D009369:Neoplasms / Q000175:diagnosis; D013055:Spectrophotometry, Infrared / Q000379:methods; D013194:Staining and Labeling / Q000379:methods*; D045162:Thiazolidinediones / Q000032:analysis*
chemical_list: D045162:Thiazolidinediones; D007208:Indocyanine Green