Aspects of DNA assembly: Extension, lithography and recognition

In this paper we describe the micromanipulation of single genomic DNA and t he lithographic representation of its sequence information on a biochip, An optical tweezer combined with force detection using light backscattering a nd a force cantilever is used to manipulate single molecules. Using this we probe the flexibility of a DNA template and its use as a mechanical detect or to study DNA-protein interactions. We then use this approach to directly monitor the extension of a single DNA polymer beyond its contour length, d ue to its unwinding, induced by the polymerization of RecA protein. Finally the application of a localized light source for bio-molecular lithography is presented. We describe micropatterning DNA molecules on a solid substrat e for specific bio-molecular recognition. The ability to manipulate, fabric ate addressable DNA arrays and specifically recognize genomic DNA molecules opens the possibility of studying the mechanisms underlying genetic proces ses and biological networks.