Improved DNA straightening and attachment via optimal Mg2+ ionic bonding under electric field for AFM imaging in liquid phase. (September 2019)

• Record Type: Journal Article
• Authors: Liu, Ziyu; Xu, Hongmei; Wang, Ying; Yang, Fan; Yin, Yaoting; Zhang, Sheng; Weng, Zhankun; Song, Zhengxun; Wang, Zuobin
• Is Part Of: Micron. Volume 124(2019)
• Publication Date: 2019-09
• Subjects: DNA straightening -- Liquid phase -- Electric field -- Ion modification -- AFM imaging; Microscopy -- Periodicals; Electron Probe Microanalysis -- Periodicals; Microscopy -- Periodicals; Microscopie -- Périodiques; Microscopy; Periodicals; 502.82
• DOI: 10.1016/j.micron.2019.04.006
• Languages: English
• ISSNs: 0968-4328

Abstract

Highlights: Proposed a new method to improve DNA straightening under an applied electric field. The straightened DNA could be successfully imaged and manipulated in liquid media by quantitative AFM imaging. Mg 2+ ion-modified mica substrate enabled DNA straightening under DC electric field. The new technique is of great significance for the biomedicine field. Abstract: In this research, a novel method is proposed to improve DNA straightening under an applied electric field to facilitate imaging in a liquid phase by modifying the substrate with varying Mg 2+ ion concentrations. A two-dimensional network of DNA structures was successfully stretched on Mg 2+ -modified mica substrates under a DC electric field (1 V, 1 A) and imaged in gaseous and aqueous phases by atomic force microscopy. The results revealed that an optimum concentration of Mg 2+ ion (4.17 μmol/ml) allowed DNA straightening under an electric field, thus facilitating its imaging in the liquid phase. Furthermore, DNA adhesion under different concentrations of Mg 2+ was measured and a maximum adhesion force of 76.19 pN was achieved. This vital work has great potential in gene knockout and targeted gene editing.