Mesoscopic oblique plane microscopy via light-sheet mirroring

Understanding the intricate interplay and inter-connectivity of biological processes across an entire organism is important in various fields of biology, including cardiovascular research, neuroscience, and developmental biology. Here, we present a mesoscopic oblique plane microscope (OPM) that enables whole organism imaging with high speed while revealing fine details such as endothelial nuclei. A microprism underneath the sample enhances the axial resolution and optical sectioning through total internal reflection of the light sheet. Through rapid refocusing of the light sheet, the imaging depth is extended up to threefold while keeping the axial resolution constant. Using low magnification objectives with a large field of view, we realize mesoscopic imaging over a volume of 3.7 mm x 1.5 mm x 1 mm with similar to 2.3 mu m lateral and similar to 9.2 mu m axial resolution. Applying the mesoscopic OPM, we demonstrate in vivo and in toto whole organism imaging of the zebrafish vasculature and its endothelial nuclei, and blood flow dynamics at 12 Hz acquisition rate, resulting in a quantitative map of blood flow across the entire organism.(c) 2023 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Automated summary

Understanding the intricate interplay and inter-connectivity of biological processes across an entire organism is crucial in various fields of biology. The mesoscopic oblique plane microscope (OPM) presented here allows high-speed whole organism imaging with fine details revealed. By utilizing a microprism, the axial resolution and optical sectioning are enhanced through total internal reflection. The imaging depth is extended up to threefold while maintaining constant axial resolution through rapid refocusing of the light sheet. The mesoscopic OPM enables in vivo and in toto whole organism imaging, demonstrating quantitative mapping of blood flow dynamics in zebrafish vasculature and endothelial nuclei at a 12 Hz acquisition rate.