title: Ionic effect on combing of single DNA molecules and observation of their force-induced melting by fluorescence microscopy.
abstract: Molecular combing is a powerful and simple method for aligning DNA molecules onto a surface. Using this technique combined with fluorescence microscopy, we observed that the length of lambda-DNA molecules was extended to about 1.6 times their contour length (unextended length, 16.2 microm) by the combing method on hydrophobic polymethylmetacrylate coated surfaces. The effects of sodium and magnesium ions and pH of the DNA solution were investigated. Interestingly, we observed force-induced melting of single DNA molecules.
authors.affiliation: Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Science, Beijing 100080, China.
authors.forename: Yu-Ying
authors.initials: YY
authors.lastname: Liu
authors.forename: Peng-Ye
authors.initials: PY
authors.lastname: Wang
authors.forename: Shuo-Xing
authors.initials: SX
authors.lastname: Dou
authors.forename: Wei-Chi
authors.initials: WC
authors.lastname: Wang
authors.forename: Ping
authors.initials: P
authors.lastname: Xie
authors.forename: Hua-Wei
authors.initials: HW
authors.lastname: Yin
authors.forename: Xing-Dong
authors.initials: XD
authors.lastname: Zhang
authors.forename: Xu Guang
authors.initials: XG
authors.lastname: Xi
mesh_terms: D010582:Bacteriophage lambda / Q000737:chemistry; D001696:Biomechanical Phenomena; D004279:DNA, Viral / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D008274:Magnesium / Q000737:chemistry; D008856:Microscopy, Fluorescence; D009690:Nucleic Acid Conformation; D044367:Phase Transition; D019904:Polymethyl Methacrylate / Q000737:chemistry; D012964:Sodium / Q000737:chemistry; D013499:Surface Properties
chemical_list: D004279:DNA, Viral; D019904:Polymethyl Methacrylate; D012964:Sodium; D008274:Magnesium