ACRIDINE ORANGE (AO) stain and fluorescence microscopy have been widely used for the evaluation of gynecologic exfoliative cytology.1,2 Basically, it has been noted that the desoxyribonucleic acid (DNA) of the nucleus of a cell fluoresces with a yellowish-green color and that the cytoplasmic ribonucleic acid (RNA) appears orange-pink in color. The pH of the stain affects the colors visualized.
Although there has been some conflict as to whether neoplastic cells can be adequately evaluated by AO technique, other pertinent observations have been made. Red blood cells do not fluoresce and thus do not interfere with examination of the specimen.2 Microorganisms, on the other hand, do fluoresce with a bright orange-red color, which vividly contrasts with the colors of DNA and RNA. If sufficient organisms are present, they may actually interfere with accurate cytologic visualization.2 Along these lines, the AO method has been used for the diagnosis of
Kushnick T, Christos NJ. Acridine Orange Fluorescence: A New Technique for Examination of Cerebrospinal Fluid. JAMA. 1963;186(3):264–265. doi:10.1001/jama.1963.63710030040021c
Coronavirus Resource Center
Customize your JAMA Network experience by selecting one or more topics from the list below.
Create a personal account or sign in to: