Permanence of fungi-fluor epifluorescence stain to detect microsporidia

OBJECTIVE: Epifluorescence microscopy, a methodology for the screening of b odily fluids and tissue specimens for microsporidia species, was directed t o evaluate the retention of epifluorescence of fixed and stained specimens over time. METHODS: Thirty samples of stool, bodily fluids, duodenal touch preparation s, and biopsies, were tested for the retention of their epifluoresence usin g the Fungi-Fluor procedure. Specimens were examined under a 330- to 380-nm UV filter at the time of preparation, 3 wk later, and then at monthly inte rvals for 18 months. All specimens were reevaluated for the presence or abs ence of fluorescence and any decrement of fluorescence over time. No specia l preservation techniques were used on any of the slides. RESULTS: All 30 specimens maintained their epifluorescence from the time of slide preparation to 18 month later. No decrement in fluorescence was note d in any sample examined. Accuracy and ease of spore identification was mai ntained. CONCLUSIONS: Epifluorescence microscopy demonstrates the utility of this te chnique for archival study of microsporidia-containing specimens over prolo nged periods of time. (C) 2000 by Am. Cell. of Gastroenterology).