Ionic effect on combing of single DNA molecules and observation of their force-induced melting by fluorescence microscopy.
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.
Liu
Yu-Ying
YY
Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Science, Beijing 100080, China.
Wang
Peng-Ye
PY
Dou
Shuo-Xing
SX
Wang
Wei-Chi
WC
Xie
Ping
P
Yin
Hua-Wei
HW
Zhang
Xing-Dong
XD
Xi
Xu Guang
XG
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
D004279:DNA, Viral; D019904:Polymethyl Methacrylate; D012964:Sodium; D008274:Magnesium