title: Visualization of Legionella pneumophila in paraffin sections using hexamine silver.
abstract: A modification of Gomori's hexamine silver technique is given as a simple, reliable method for the nonspecific demonstration of Legionella pneumophila in paraffin sections. When tested against serogroups I to VI it was found that pretreatment with potassium dichromate rendered L. pneumophila demonstrable by the Gomori-Burtner hexamine silver solution when buffered to pH 7.8. Tissue was fixed in 10% buffered formalin and sections were cut at 3-5 microns. After treatment with 10% potassium dichromate for 1 hour at room temperature, sections are placed in the silver solution at 56 C until they develop a pale golden yellow color, at which point they are checked periodically under the microscope for optimal staining (approximately 3-4 hours). Sections are then toned, fixed and counterstained in 1% neutral red. The L. pneumophila coccobacilli stain black against a clear background, while nuclei stain red/black.
mesh_terms: D006801:Humans; D007875:Legionella / Q000302:isolation & purification*; D008709:Methenamine; D010232:Paraffin; D012834:Silver; D013194:Staining and Labeling
chemical_list: D012834:Silver; D010232:Paraffin; D008709:Methenamine