[Calcofluor-white staining in the identification of Pneumocystis carinii]

Calcofluor white stain is widely used as a fluorescent stain in mycology. Recently, it was found that by calcofluor white staining Pneumocystis carinii cysts exert a highly characteristic staining pattern. We retested fifteen clinical specimens which were known to be positive for Pneumocystis carinii (diagnosis made by a methenamine silver stain). Calcofluor white stain proved to be a simple, rapid, and inexpensive method for detecting Pneumocystis carinii in clinical specimens.