Imaging Higher-order Chromatin Structures in Single Cells Using Stochastic Optical Reconstruction Microscopy.

Higher-order chromatin organization shaped by epigenetic modifications influence the chromatin environment and subsequently regulate gene expression. Direct visualization of the higher-order chromatin structure at their epigenomic states is of great importance for understanding chromatin compaction and its subsequent effect on gene expression and various cellular processes. With the recent advances in super-resolution microscopy, the higher-order chromatin structure can now be directly visualized in situ down to the scale of ~30 nm. This protocol provides detailed description of super-resolution imaging of higher-order chromatin structure using stochastic optical reconstruction microscopy (STORM). We discussed fluorescence staining methods of DNA and histone proteins and crucial technical factors to obtain high-quality super-resolution images.