Asbury C L, van den Engh G
Department of Molecular Biotechnology, University of Washington, Seattle 98195, USA.
Biophys J. 1998 Feb;74(2 Pt 1):1024-30. doi: 10.1016/s0006-3495(98)74027-5.
DNA molecules can be manipulated in aqueous solution in a manner analogous to optical trapping. Due to the induction of an electric dipole, DNA molecules are pulled by a gradient force to regions of high electric field strength. Molecules can be locally trapped in an oscillating field using strips of very thin gold film to generate strong electric fields with steep gradients. Spatial control over the trapped molecules is achieved because they are confined to a width of approximately 5 microm along the edges of the gold-film strips. By mixing static and oscillating electric fields, trapped molecules can be moved from one edge to another or made to follow precise trajectories along the edges. This phenomenon should be useful in microdevices for manipulation of small quantities or single molecules of DNA.
DNA分子能够在水溶液中以类似于光镊的方式进行操控。由于电偶极子的感应作用，DNA分子会被梯度力拉向高电场强度区域。利用非常薄的金膜条带在振荡场中可产生具有陡峭梯度的强电场，从而将分子局部捕获。由于捕获的分子被限制在沿金膜条带边缘约5微米的宽度范围内，因此实现了对捕获分子的空间控制。通过混合静电场和振荡电场，捕获的分子可以从一个边缘移动到另一个边缘，或者沿着边缘遵循精确的轨迹移动。这种现象在用于操控少量或单个DNA分子的微器件中应该会很有用。
