LAUSR

Super-resolution microscopy captures detailed information on cellular structures. Zhanghao et al. describe polarization structured illumination microscopy (pSIM), which combines the benefits of structured illumination for live-cell super-resolution imaging with detailed orientation mapping, giving richer insight into the organization of labeled structures. pSIM can be carried out on commercially available structured illumination microscopes in 2D, in 3D, and in TIRF mode. It determines polarization using analysis in a spatio-angular hyperspace on the basis of the extent of a fluorophore’s excitation by polarized light. The researchers demonstrated the approach by imaging filamentous structures in cells, including cytoskeletal networks and λ DNA. They also used pSIM to show the side-by-side actin ring structures in the membrane-associated periodic skeleton of hippocampal neurons. Beyond these experiments, they monitored changes in polarization in microtubules in living mammalian cells.