Acridine Orange Fluorescent Stain for Fungi

Abstract

<h3>Introduction</h3> Acridine orange has been used for some time as a fluorescent stain for nucleoproteins and for tissue mucopolysaccharides.⁶It has also found use as a vital stain for blood parasites.⁸ By accident it was found that the technique of Hicks and Matthaei for the fluorescent staining of mucin⁴would also stain fungi in tissue sections which would then fluoresce under blue-violet light.⁷This finding led to a study of further applications of this method to demonstrate structural details of the fungi themselves and as diagnostic aids in clinical evaluations. <h3>Materials and Methods</h3><h3>Microscope and Filters.—</h3> These studies were done using a Reichert Zetopan microscope with fluorescent attachments. Results were checked periodically with an ordinary binocular microscope and lamp equipped with filters for fluorescent microscopy⁷to insure adaptability to this apparatus. In the latter apparatus a Leitz or Zeiss bluelight fluorescence filter (BG 12, 4 mm.