School of Chemistry and Collaborative Optical Spectroscopy, Micromanipulation and Imaging Center (COSMIC), University of Edinburgh, Joseph Black Building, The King's Buildings, West Mains Road, EH9 3JJ Edinburgh, UK.
Biopolymers. 2011 May;95(5):290-7. doi: 10.1002/bip.21574. Epub 2010 Dec 23.
With the expansion of super-resolution fluorescence microscopy methods, it is now possible to access the organization of cells and materials at the nanoscale by optical means. This review discusses recent progress in super-resolution imaging of isolated and cell DNA using single-molecule localization methods. A high labeling density of photoswitchable fluorophores is crucial for these techniques, which can be provided by sequence independent DNA stains in which photoblinking reactions can be induced. In particular, unsymmetrical cyanine intercalating dyes in combination with special buffers can be used to image isolated DNA with a spatial resolution of 30-40 nm. For super-resolution imaging of chromatin, cell permeant cyanine dyes that bind the minor groove of DNA have the potential to become a useful alternative to the labeling of histones and other DNA-associated proteins. Other recent developments that are interesting in this context such as high density labeling methods or new DNA probes with photoswitching functionalities are also surveyed. Progress in labeling, optics, and single-molecule localization algorithms is being rapid, and it is likely to provide real insight into DNA structuring in cells and materials.
随着超分辨率荧光显微镜方法的扩展，现在可以通过光学手段来获取纳米尺度下细胞和材料的组织。本文讨论了使用单分子定位方法对分离的和细胞内 DNA 进行超分辨率成像的最新进展。对于这些技术，光开关荧光染料的高标记密度是至关重要的，这可以通过序列独立的 DNA 染色剂来提供，其中可以诱导光致漂白反应。特别是，不对称的花菁类嵌入染料与特殊的缓冲液结合，可以用于以 30-40nm 的空间分辨率对分离的 DNA 进行成像。对于染色质的超分辨率成像，能够结合 DNA 小沟的细胞通透性花菁染料有可能成为标记组蛋白和其他与 DNA 相关蛋白的有用替代方法。本文还调查了其他一些在这方面很有趣的最新进展，例如高密度标记方法或具有光致开关功能的新 DNA 探针。在标记、光学和单分子定位算法方面的进展正在迅速推进，这很可能为我们提供对细胞和材料中 DNA 结构的深入了解。
