title: Fixation effect of SurePath preservative fluids using epidermal growth factor receptor mutation-specific antibodies for immunocytochemistry.
abstract: BACKGROUND
  Cytological diagnosis of respiratory disease has become important, not only for histological typing using immunocytochemistry (ICC) but also for molecular DNA analysis of cytological material. The aim of this study was to investigate the fixation effect of SurePath preservative fluids.
  
  
  METHODS
  Human lung cancer PC9 and 11-18 cell lines, and lung adenocarcinoma cells in pleural effusion, were fixed in CytoRich Blue, CytoRich Red, 15% neutral-buffered formalin, and 95% ethanol, respectively. PC9 and 11-18 cell lines were examined by ICC with epidermal growth factor receptor (EGFR) mutation-specific antibodies, the EGFR mutation DNA assay, and fluorescence in situ hybridization. The effect of antigenic storage time was investigated in lung adenocarcinoma cells in pleural effusion by ICC using the lung cancer detection markers.
  
  
  RESULTS
  PC9 and 11-18 cell lines in formalin-based fixatives showed strong staining of EGFR mutation-specific antibodies and lung cancer detection markers by ICC as compared with ethanol-based fixatives. DNA preservation with CytoRich Blue and CytoRich Red was superior to that achieved with 95% ethanol and 15% neutral-buffered formalin fixatives, whereas EGFR mutations by DNA assay and EGFR gene amplification by fluorescence in situ hybridization were successfully identified in all fixative samples. Although cytoplasmic antigens maintained high expression levels, expression levels in nuclear antigens fell as storage time increased.
  
  
  CONCLUSIONS
  These results indicate that CytoRich Red is not only suitable for ICC with EGFR mutation-specific antibodies, but also for DNA analysis of cytological material, and is useful in molecular testing of lung cancer, for which various types of analyses will be needed in future.
authors.affiliation: Department of Diagnostic Pathology, Kurume University Hospital, Kurume, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Kawahara
authors.forename: Tomoki
authors.initials: T
authors.lastname: Taira
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Abe
authors.forename: Kosuke
authors.initials: K
authors.lastname: Watari
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Murakami
authors.forename: Chihiro
authors.initials: C
authors.lastname: Fukumitsu
authors.forename: Yorihiko
authors.initials: Y
authors.lastname: Takase
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: Koichi
authors.initials: K
authors.lastname: Azuma
authors.forename: Jun
authors.initials: J
authors.lastname: Akiba
authors.forename: Mayumi
authors.initials: M
authors.lastname: Ono
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Kage
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics; D000077192:Adenocarcinoma of Lung; D000906:Antibodies / Q000276:immunology*; D045744:Cell Line, Tumor; D066246:ErbB Receptors / Q000235:genetics* / Q000276:immunology; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008175:Lung Neoplasms / Q000175:diagnosis / Q000235:genetics*; D009154:Mutation; D016707:Tissue Fixation / Q000379:methods*
chemical_list: D000906:Antibodies; D066246:ErbB Receptors
keywords: cell block; epidermal growth factor receptor mutation-specific antibodies; immunocytochemistry; liquid-based cytology; lung cancer