Multimodal Microscopy Imaging of Cardiac Collagen Network: Are We Looking at the Same Structures?

Visualization of collagen fibers in cardiac tissues is essential for clinical diagnosis and pathological analysis of cardiac fibrosis. Selecting a proper imaging method is still challenging for researchers and clinicians who want to determine specific information about the collagen network in cardiac tissues. We examined fibrillar collagen network from mouse ventricular myocardium by commonly available light microscopy techniques using our home-built multimodal microscope. Myocardial slices were unstained or stained with either Picrosirius red or collagen type I antibody/dye conjugation, then imaged by polarized light, confocal fluorescence, second harmonic generation (SHG), two-photon excited fluorescence (TPEF), and stimulated emission depletion (STED) microscopy techniques. This study is intended to serve as a reference for basic research and clinical evaluation of fibrillar collage network in cardiac tissues.