Tissue clearing‐based method for unobstructed three‐dimensional imaging of mouse penis with subcellular resolution

Abstract

Although mice are widely used to elucidate factors contributing to penile disorders and develop treatment options, quantification of tissue changes upon intervention is either limited to minuscule tissue volume (histology) or acquired with limited spatial resolution (MRI/CT). Thus, imaging method suitable for expeditious acquisition of the entire mouse penis with subcellular resolution is described that relies on both aqueous‐ (clear, unobstructed brain imaging cocktails and computational analysis) and solvent‐based (fluorescence‐preserving capability imaging of solvent‐cleared organs) tissue optical clearing (TOC). The combined TOC approach allows to image mouse penis innervation and vasculature with unprecedented detail and, for the first time, reveals the three‐dimensional structure of murine penis fibrocartilage.

Can Developments in Tissue Optical Clearing Aid Super-Resolution Microscopy Imaging?

“…Although when categorized based on the chemical nature of the main chemical used, almost all TOC methods fall into four general categories: organic solvents, high-refractive index aqueous solutions, hyperhydration solutions and tissue transformation techniques [19,27]. Newer, advanced TOC protocols often apply chemicals from distinct TOC approaches [28][29][30] and as such take advantage of specific strengths from each of their forebears. For example, the PEGASOS method [28], even suitable for whole-body clearing (which proves its wide applicability and compatibility with different organs of interest), consists of (1) a decalcification step with EDTA, (2) Quadrol-based tissue decolorization, (3) tert-butanol-mediated tissue delipidation and, finally, (4) refractive index (RI) matching with organic solvents.…”