Super-resolution imaging of fluorescent dipoles via polarized structured illumination microscopy

Super-resolution imaging of fluorescent dipoles via polarized structured illumination microscopy

Karl Zhanghao, Xingye Chen, Wenhui Liu, Meiqi Li, Yiqiong Liu, Yiming Wang, Sha Luo, Xiao Wang, Chunyan Shan, Hao Xie, Juntao Gao, Xiaowei Chen, Dayong Jin, Xiangdong Li, Yan Zhang, Qionghai Dai & Peng Xi 

https://doi.org/10.1038/s41467-019-12681-w

?Fluorescence polarization microscopy images both the intensity and orientation of fluorescent dipoles and plays a vital role in studying molecular structures and dynamics of bio-complexes. However, current techniques remain difficult to resolve the dipole assemblies on subcellular structures and their dynamics in living cells at super-resolution level. Here we report polarized structured illumination microscopy (pSIM), which achieves super-resolution imaging of dipoles by interpreting the dipoles in spatio-angular hyperspace. We demonstrate the application of pSIM on a series of biological filamentous systems, such as cytoskeleton networks and λ-DNA, and report the dynamics of short actin sliding across a myosin-coated surface. Further, pSIM reveals the side-by-side organization of the actin ring structures in the membrane-associated periodic skeleton of hippocampal neurons and images the dipole dynamics of green fluorescent protein-labeled microtubules in live U2OS cells. pSIM applies directly to a large variety of commercial and home-built SIM systems with various imaging modality.