Surface manipulation and immobilization of single DNA wire on Au surface
|Sho Fujii , Katsuhiko Kanaizuka , Tetsuaki Okamoto , Shoichi Toyabe , Eiro Muneyuki , Masa-aki Haga|
Chuo university, 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
DNA alignment techniques have been required in order to analyze its genetic code and to use DNA as a one-dimensional wire template. Although several methods of DNA alignment had been reported previously, for example electrophoresis, transfer-printing on polydimethylsiloxane, and molecular combing, it was difficult to control the number and position of DNA on a solid surface. In this study, we introduce a new methodology for DNA alignment using Nd: YAG laser (1064 nm). We observed for the first time that focusing of Nd: YAG laser beam on Au thin film surface induced a rapid pulling of DNA molecules near the focal point in handmade liquid cell. l DNA was stained with SYBR Gold for fluorescence microscope observation. One end of l DNA strands was labeled with thiol and immobilized by self-assembly of thiol group on an Au surface. After the immobilization, the other end of strands was free in solution, and the elongation was observed near the laser focal point as shown in Fig 1. In the case of bare Au surface, the elongated DNA was pinned upon a touch of laser focal point with the elongated edge of DNAs. On the other hand, on the bovine serum albumin modified Au surface DNA was not pinned. The present laser pulling phenomenon was strongly dependent on the thickness of Au film and the solid substrate. This optical manipulation method opens the door to fabricating single DNA nanowires and junctions.
Presentation: Short communication at SMCBS'2009 International Workshop, by Sho Fujii
See On-line Journal of SMCBS'2009 International Workshop
Submitted: 2009-08-31 05:28 Revised: 2009-08-31 13:10