@article {70161, title = {Mesoscale volumetric fluorescence imaging at nanoscale resolution by photochemical sectioning}, journal = {Science}, volume = {390}, year = {2025}, month = {2025 Oct 16}, pages = {eadr9109}, abstract = {

Optical nanoscopy of intact biological specimens has been transformed by recent advancements in hydrogel-based tissue clearing and expansion, enabling the imaging of cellular and subcellular structures with molecular contrast. However, existing high-resolution fluorescence microscopes are physically limited by objective-to-specimen distance, which prevents the study of whole-mount specimens without physical sectioning. To address this challenge, we developed a photochemical strategy for spatially precise sectioning of specimens. By combining serial photochemical sectioning with lattice light-sheet imaging and petabyte-scale computation, we imaged and reconstructed axons and myelin sheaths across entire mouse olfactory bulbs at nanoscale resolution. An olfactory bulb{\textendash}wide analysis of myelinated and unmyelinated axons revealed distinctive patterns of axon degeneration and de-/dysmyelination in the neurodegenerative brain, highlighting the potential for peta- to exabyte-scale super-resolution studies using this approach. High-resolution microscopes have a short working distance, making it difficult to see deep within large biological samples such as an intact brain. Slicing the tissue with a blade can reach deeper, but this often distorts or destroys the fine structures that scientists want to study. By embedding a sample in a light-sensitive hydrogel, Wang et al. demonstrated a gentler approach using a precise ray or sheet of light to dissolve or cut away tissue layer by layer. After each layer is removed, the newly exposed surface is imaged, allowing for a complete, high-resolution, three-dimensional reconstruction without damaging physical contact.\ 

bioRxiv preprint: https://www.biorxiv.org/content/10.1101/2024.08.01.605857v1

}, doi = {10.1126/science.adr9109}, url = {https://www.science.org/doi/abs/10.1126/science.adr9109}, author = {Wei Wang and Xiongtao Ruan and Gaoxiang Liu and Daniel E. Milkie and Wenping Li and Eric Betzig and Srigokul Upadhyayula and Ruixuan Gao} }