Chemical Research in Chinese Universities ›› 2020, Vol. 36 ›› Issue (2): 227-236.doi: 10.1007/s40242-020-9107-4

• Reviews • Previous Articles     Next Articles

Characterization of 3D DNA Assemblies Using Cryogenic Electron Microscopy

WANG Mingyang1,2,3, DUAN Jialin4, DAI Lizhi3, XIN Xiaodong1,3, WANG Fangfang4, LI Zheng1,5, TIAN Ye2,3,6   

  1. 1. School of Materials Science and Engineering, Xiangtan University, Xiangtan 411105, P. R. China;
    2. Shenzhen Research Institute, Nanjing University, Shenzhen 518057, P. R. China;
    3. College of Engineering and Applied Sciences, National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing 210093, P. R. China;
    4. National Facility for Protein Science in Shanghai, Zhangjiang Lab, Shanghai 201210, P. R. China;
    5. School of Physics and Optoelectronic Engineering, Ludong University, Yantai 264025, P. R. China;
    6. Chemistry and Biomedicine Innovation Center, Nanjing University, Nanjing 210023, P. R. China
  • Received:2019-12-25 Revised:2020-02-04 Online:2020-04-01 Published:2020-03-18
  • Contact: LI Zheng, TIAN Ye E-mail:ytian@nju.edu.cn;3636@ldu.edu.cn
  • Supported by:
    Supported by the National Natural Science Foundation of China(Nos.11835008, 21971109, 21834004), the National Key R&D Program of China(No.2017YFF0105000), the Special Project of Changsha-Zhuzhou-Xiangtan National Independent Innovation Demonstration Area, China(Nos.2017GK2293, 2018XK2303), the Jiangsu Youth Fund, China(No.BK20180337), the Fundamental Research Funds for the Central Universities, China(No.14380151), the Program for Innovative Talents and Entrepreneur in Jiangsu Province, China(No.133181), the Shenzhen International Cooperation Research Project, China(No. GJHZ20180930090602235) and the Nanjing Science and Technology Innovation Project for Oversea Scholars' Merit Funding, China (No.133170).

Abstract: DNA nanotechnology utilizes DNA double strands as building units for self-assembly of DNA nanostructures. The specific base-pairing interaction between DNA molecules is the basis of these assemblies. After decades of development, this technology has been able to construct complex and programmable structures. With the increase in delicate nature and complexity of the synthesized nanostructures, a characterization technology that can observe these structures in three dimensions has become necessary, and developing such a technology is considerably challenging. DNA assemblies have been studied using different characterization methods including atomic force microscopy (AFM), scanning electron microscopy(SEM), and transmission electron microscopy(TEM). However, the three-dimensional(3D) DNA assemblies always collapse locally due to the dehydration during the drying process. Cryogenic electron microscopy(cryo-EM) can overcome the challenge by maintaining three-dimensional morphologies of the cryogenic samples and reconstruct the 3D models from cryogenic samples accordingly by collecting thousands of two-dimensional(2D) projection images, which can restore their original morphologies in solution. Here, we have reviewed several typical cases of 3D DNA-assemblies and highlighted the applications of cryo-EM in characterization of these assemblies. By comparing with some other characterization methods, we have shown how cryo-EM promoted the development of structural characterization in the field of DNA nanotechnology.

Key words: DNA nanotechnology, DNA-assembly, Cryogenic electron microscopy