Complete Extension of Chromosomal DNA and Its Manipulation Using Optically-Driven Micro-Structures

This paper presents a novel method for extension and manipulation of chromosomal DNA using electroosmotic flow (EOF) and optically-driven micro-structures, which is intended for the use in nanotechnology-based genomic studies. Chromosomal DNA fibers are first hydrodynamically extended to the full length between micro-pillars on a substrate by EOF. In order to manipulate single chromosomal DNA fibers, we developed micro-hook and micro-bobbin, which were fabricated with SU-8 photo resist and grasped by focused laser beams. A targeted position of an extended DNA fiber was picked up with the micro-hook and translocated by moving the hook. To manipulate a whole DNA fiber, an extended fiber was wound to be compact using micro-bobbins. These handling techniques realize the observation of single chromosomal DNA molecules with high spatial resolution