[New fluorescent microscopical technique in diagnostic microbiology (author's transl)].

The practicability of 4',6-diamidino-2-phenylindole (DAPI) in the fluorescent microscopical demonstration of bacterial and other cellular structures for medical diagnostic purposes was investigated. Polar bodies in diphtheria bacilli and spores of spore-forming bacteria showed up well. The demonstration of phagocytosed bacteria in urinary sediment and the morphology of human spermatozoa are particularly impressive. Noteworthy advantages of DAPI are its stability (no bleaching of stained preparations), its use in minute quantities, rapid staining (within minutes), and simplicity of use.