Orientation and Positioning of DNA Molecules with an Electric Field Technique

Abstract

A controlled handling of single molecules is essential for the fabrication and the investigation of devices based on molecules. We present here the implementation of an electric field based method used to manipulate DNA molecules by means of lithographically patterned metallic electrodes. We optimized the geometry of the lithographic structures to favor a precise positioning of the molecules via dielectrophoresis. This process is combined with an orientation of the molecules parallel to the electric field lines due to their induced dipole moment. The relatively high polarizability of the DNA molecules in solution is essential to achieve these manipulations. We expect this method to be softer than the stretching of molecules using a receding meniscus. The visualization of the molecules was achieved using fluorescence microscopy.