中国物理B ›› 2016, Vol. 25 ›› Issue (7): 78201-078201.doi: 10.1088/1674-1056/25/7/078201

• INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY • 上一篇    下一篇

Direct observation of λ -DNA molecule reversal movement within microfluidic channels under electric field with single molecule imaging technique

Fengyun Yang(杨凤云), Kaige Wang(王凯歌), Dan Sun(孙聃), Wei Zhao(赵伟), Hai-qing Wang(王海青), Xin He(何鑫), Gui-ren Wang(王归仁), Jin-tao Bai(白晋涛)   

  1. 1 Institute of Photonics & Photo-Technology, National Center for International Research of Photoelectric Technology & Nano-functional Materials, State Key Laboratory of Cultivation Base for Photoelectric Technology and Functional Materials, Key Laboratory of Optoelectronic Technology of Shaanxi Province, Northwest University, Xi’an 710069, China;
    2 Mechanical Engineering Department & Biomedical Engineering Program, University of South Carolina, Columbia SC 29208, USA
  • 收稿日期:2016-02-02 修回日期:2016-03-22 出版日期:2016-07-05 发布日期:2016-07-05
  • 通讯作者: Kaige Wang E-mail:wangkg@nwu.edu.cn
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant No. 61378083), the International Cooperation Foundation of the National Science and Technology Major Project of the Ministry of Science and Technology of China (Grant No. 2011DFA12220), the Major Research Plan of National Natural Science Foundation of China (Grant No. 91123030), and the Natural Science Foundation of Shaanxi Province of China (Grant Nos. 2010JS110 and 2013SZS03-Z01).

Direct observation of λ -DNA molecule reversal movement within microfluidic channels under electric field with single molecule imaging technique

Fengyun Yang(杨凤云)1, Kaige Wang(王凯歌)1, Dan Sun(孙聃)1, Wei Zhao(赵伟)1,2, Hai-qing Wang(王海青)1, Xin He(何鑫)1, Gui-ren Wang(王归仁)2, Jin-tao Bai(白晋涛)1   

  1. 1 Institute of Photonics & Photo-Technology, National Center for International Research of Photoelectric Technology & Nano-functional Materials, State Key Laboratory of Cultivation Base for Photoelectric Technology and Functional Materials, Key Laboratory of Optoelectronic Technology of Shaanxi Province, Northwest University, Xi’an 710069, China;
    2 Mechanical Engineering Department & Biomedical Engineering Program, University of South Carolina, Columbia SC 29208, USA
  • Received:2016-02-02 Revised:2016-03-22 Online:2016-07-05 Published:2016-07-05
  • Contact: Kaige Wang E-mail:wangkg@nwu.edu.cn
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant No. 61378083), the International Cooperation Foundation of the National Science and Technology Major Project of the Ministry of Science and Technology of China (Grant No. 2011DFA12220), the Major Research Plan of National Natural Science Foundation of China (Grant No. 91123030), and the Natural Science Foundation of Shaanxi Province of China (Grant Nos. 2010JS110 and 2013SZS03-Z01).

摘要:

The electrodynamic characteristics of single DNA molecules moving within micro-/nano-fluidic channels are important in the design of biomedical chips and bimolecular sensors. In this study, the dynamic properties of λ -DNA molecules transferring along the microchannels driven by the external electrickinetic force were systemically investigated with the single molecule fluorescence imaging technique. The experimental results indicated that the velocity of DNA molecules was strictly dependent on the value of the applied electric field and the diameter of the channel. The larger the external electric field, the larger the velocity, and the more significant deformation of DNA molecules. More meaningfully, it was found that the moving directions of DNA molecules had two completely different directions: (i) along the direction of the external electric field, when the electric field intensity was smaller than a certain threshold value; (ii) opposite to the direction of the external electric field, when the electric field intensity was greater than the threshold electric field intensity. The reversal movement of DNA molecules was mainly determined by the competition between the electrophoresis force and the influence of electro-osmosis flow. These new findings will theoretically guide the practical application of fluidic channel sensors and lab-on-chips for precisely manipulating single DNA molecules.

关键词: reversal movement, electrophoresis, electroosmosis, electric field threshold value

Abstract:

The electrodynamic characteristics of single DNA molecules moving within micro-/nano-fluidic channels are important in the design of biomedical chips and bimolecular sensors. In this study, the dynamic properties of λ -DNA molecules transferring along the microchannels driven by the external electrickinetic force were systemically investigated with the single molecule fluorescence imaging technique. The experimental results indicated that the velocity of DNA molecules was strictly dependent on the value of the applied electric field and the diameter of the channel. The larger the external electric field, the larger the velocity, and the more significant deformation of DNA molecules. More meaningfully, it was found that the moving directions of DNA molecules had two completely different directions: (i) along the direction of the external electric field, when the electric field intensity was smaller than a certain threshold value; (ii) opposite to the direction of the external electric field, when the electric field intensity was greater than the threshold electric field intensity. The reversal movement of DNA molecules was mainly determined by the competition between the electrophoresis force and the influence of electro-osmosis flow. These new findings will theoretically guide the practical application of fluidic channel sensors and lab-on-chips for precisely manipulating single DNA molecules.

Key words: reversal movement, electrophoresis, electroosmosis, electric field threshold value

中图分类号:  (Single molecule manipulation of proteins and other biological molecules)

  • 82.37.Rs
87.15.H- (Dynamics of biomolecules) 87.15.Tt (Electrophoresis) 87.19.rh (Fluid transport and rheology)