title: Conventional and confocal fluorescence microscopy of collagen fibers in the heart.
abstract: The arrangement of collagen fibers has previously been studied with picrosirius red (PSR) staining and brightfield microscopy. We discovered that PSR staining can also be visualized by fluorescence microscopy. PSR-stained collagen was strongly fluorescent using excitation and barrier filters for rhodamine, and distracting background cytoplasmic fluorescence was drastically reduced with phosphomolybdic acid (PMA) treatment before PSR staining. The PMA-PSR fluorescence method was more sensitive than the brightfield PSR or PMA-PSR method, and permitted confocal microscopic study. We applied the method to the study of collagen fiber three-dimensional arrangement in perimysial and endomysial septa of the heart, showing the three-dimensional course of the fibers in stereo views generated by confocal microscopy. The PMA-PSR fluorescence method should be generally useful for accurately determining collagen fiber three-dimensional arrangement, a necessary prelude to mechanical modeling of collagen-reinforced tissues.
authors.affiliation: Department of Pediatrics, Duke University Medical Center, Durham, North Carolina 27710.
authors.forename: P C
authors.initials: PC
authors.lastname: Dolber
authors.forename: M S
authors.initials: MS
authors.lastname: Spach
mesh_terms: D000818:Animals; D001391:Azo Compounds; D003094:Collagen / Q000032:analysis*; D004285:Dogs; D006346:Heart Septum / Q000737:chemistry*; D008853:Microscopy; D008856:Microscopy, Fluorescence; D008982:Molybdenum; D010756:Phosphoric Acids; D010851:Picrates; D013194:Staining and Labeling
chemical_list: D001391:Azo Compounds; D010756:Phosphoric Acids; D010851:Picrates; C009798:C.I. direct red 80; D008982:Molybdenum; D003094:Collagen; C003125:phosphomolybdic acid