title: Wet autoclave pretreatment improves the visualization of silver-stained nucleolar organizer-region-associated proteins in routinely formalin-fixed and paraffin-embedded tissues.
abstract: This study describes the effect of wet autoclave pretreatment of routinely formalin-fixed and paraffin-embedded tissues on silver-stained nucleolar organizer-region-associated proteins (AgNORs) staining. The treatment of sections at superheated steam temperature (120 degrees C) before silver incubation leads to a significantly better discrimination of single-interphase AgNORs. Counting "black dots" both by eye and by means of a computer-aided image-analyzing system revealed considerably higher AgNOR mean numbers per nucleus in all pretreated cases when compared with the respective untreated controls. However, mean AgNOR numbers increased after autoclave pretreatment in a nonlinear manner (pairwise comparison by means of Spearman's Rank correlation coefficient: rho = 0.5), whereas measurement of the AgNOR area was less influenced by autoclave pretreatment (rho = 0.8). It is concluded that wet autoclave pretreatment of routinely formalin-fixed and paraffin-embedded archival material should be applied before AgNOR staining, particularly when quantitation of AgNORs involves counting procedures.
authors.affiliation: Gerhard-Domagk Institute of Pathology, University of Münster, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Ofner
authors.forename: A
authors.initials: A
authors.lastname: Bankfalvi
authors.forename: K
authors.initials: K
authors.lastname: Riehemann
authors.forename: B
authors.initials: B
authors.lastname: Bier
authors.forename: W
authors.initials: W
authors.lastname: Böcker
authors.forename: K W
authors.initials: KW
authors.lastname: Schmid
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology; D001943:Breast Neoplasms / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000473:pathology; D003110:Colonic Neoplasms / Q000473:pathology; D005557:Formaldehyde; D016591:Histocytological Preparation Techniques; D006801:Humans; D009062:Mouth Neoplasms / Q000473:pathology; D009687:Nuclear Proteins / Q000032:analysis*; D009697:Nucleolus Organizer Region / Q000737:chemistry*; D016612:Paraffin Embedding; D016622:Silver Staining; D016707:Tissue Fixation
chemical_list: D009687:Nuclear Proteins; D005557:Formaldehyde