Correlative Super-Resolution and Atomic Force Microscopy of DNA Nanostructures and Characterization of Addressable Site Defects
Correlative Super-Resolution and Atomic Force Microscopy of DNA Nanostructures and Characterization of Addressable Site Defects
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DOI：
10.1021/acsnano.1c01976
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发表时间：
2021-06-17
期刊：
影响因子：
17.1
通讯作者：
Kuang, Wan
中科院分区：
文献类型：
--
作者：
Green, Christopher M.;Hughes, William L.;Kuang, Wan
为了实现 DNA 纳米结构的实际应用，需要先进的显微镜技术来揭示限制可寻址位点可用性的因素。关联显微镜将两个或多个显微镜结合起来表征同一样品，是一种克服单个技术局限性的方法，但它在 DNA 纳米技术中的应用有限。我们开发了一种易于使用的策略，用于高分辨率、基于相关 DNA 的点积累，用于 DNA 纳米结构的纳米级形貌 (DNA-PAINT) 超分辨率和原子力显微镜 (AFM) 成像，通过一种简单而可靠的方法将 DNA 折纸选择性地结合到盖玻片上。使用这种技术，我们检查了 DNA 折纸上的可寻址“对接”位点，以区分两种缺陷情况：结构合并但不活跃的对接位点，以及未合并的对接位点。我们发现超过 75% 的缺陷对接位点被整合但不活跃，这表明未整合的链在限制可寻址位点的可用性方面发挥了次要作用。我们进一步探讨了链纯化、紫外线照射和光氧化对可用性的影响，提供了有关缺陷潜在来源和提高 DNA 纳米结构保真度的途径的见解。
To bring real-world applications of DNA nanostructures to fruition, advanced microscopy techniques are needed to shed light on factors limiting the availability of addressable sites. Correlative microscopy, where two or more microscopies are combined to characterize the same sample, is an approach to overcome the limitations of individual techniques, yet it has seen limited use for DNA nanotechnology. We have developed an accessible strategy for high resolution, correlative DNA-based points accumulation for imaging in nanoscale topography (DNA-PAINT) super-resolution and atomic force microscopy (AFM) of DNA nanostructures, enabled by a simple and robust method to selectively bind DNA origami to cover glass. Using this technique, we examined addressable "docking" sites on DNA origami to distinguish between two defect scenarios-structurally incorporated but inactive docking sites, and unincorporated docking sites. We found that over 75% of defective docking sites were incorporated but inactive, suggesting unincorporated strands played a minor role in limiting the availability of addressable sites. We further explored the effects of strand purification, UV irradiation, and photooxidation on availability, providing insight on potential sources of defects and pathways toward improving the fidelity of DNA nanostructures.