Demonstration of early lesions of muscle by infrared fluorescence microscopy.

Previous investigations demonstrated decrease or loss of IR fluorescence in certain lesions of smooth and striated muscle. These investigations were extended to diseases of skeletal muscle. Sections were stained and photographed as described (Puchtler et al. 1980). Various diseases caused significant changes of IR fluorescence. Often, IR fluorescence demonstrated lesions in muscle fibers which appeared unremarkable in direct light and/or conventional darkfield microscopy. The patterns of IR fluorescence varied widely, even within groups of diseases, e.g. muscular dystrophies. However, owing to the heterogeneity of the available material, it is not yet possible to draw conclusions concerning the diagnostic significance of different IR fluorescence patterns. Hence this report should be regarded only as a pilot study.