title: Pyronin Y as a fluorescent stain for paraffin sections.
abstract: Pyronin Y has long been used, in combination with other dyes such as Methyl Green, as a differential stain for nucleic acids in paraffin tissue sections. It also forms fluorescent complexes with double-stranded nucleic acids, especially RNA, enabling semi-quantitative analysis of cellular RNA in flow cytometry. However, the possibility of using pyronin Y as a fluorescent stain for paraffin tissue sections has rarely been investigated. We herein report that in sections stained with Methyl Green-pyronin Y, red blood cells, elastic fibre of blood vessels, zymogen granules of pancreatic acinar cells, surface membrane of heptocytes and kidney tubular cells showed strikingly strong green and/or red fluorescence, while the nuclei of cells appeared non-fluorescent. The use of confocal laser-scanning microscope greatly improved the resolution and selectivity of the fluorescent images. Staining with pyronin Y alone gave similar results in terms of fluorescence properties of the specimens. Pretreatment of paraffin sections with RNase significantly reduced cytoplasmic pyronin Y staining as judged by transmission light microscopy, but it had little effect on the fluorescence intensity of red blood cells, elastic fibres and zymogen granules.
authors.affiliation: Department of Immunology, Peking University Health Science Center, Peking University, Beijing 100083, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Li
authors.forename: Ying
authors.initials: Y
authors.lastname: Wu
authors.forename: Xiao-Ming
authors.initials: XM
authors.lastname: Gao
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000648:ultrastructure; D005456:Fluorescent Dyes; D007668:Kidney / Q000648:ultrastructure; D008099:Liver / Q000648:ultrastructure; D051379:Mice; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D010179:Pancreas / Q000648:ultrastructure; D016612:Paraffin Embedding; D011754:Pyronine; D013194:Staining and Labeling / Q000379:methods*; D013950:Thymus Gland / Q000648:ultrastructure
chemical_list: D005456:Fluorescent Dyes; D011754:Pyronine