This paper presents a novel method for manipulating single chromosomal DNA, which is intended for the use in highresolution
genomic studies. Such operations as translocation, winding and unwinding of single DNA fiber are achieved
using optically-driven micro-fabricated structures, including micro-hooks and micro-bobbins for picking-up and winding
DNA, with a typical dimension of several μm. The geometry of the laser-manipulated micro-structures is designed in
such a way that a spontaneous orientation occurs with its major axis parallel to the laser beam and accepts a DNA fiber.
While monitoring under a fluorescence microscope, yeast chromosomal DNA is first extended to the full length by
electroosmotic flow. Then the micro-hooks are dispensed in the solution, and a DNA fiber is picked up with the microhook
which is driven by a focused laser beam, to separate the targeted DNA from the others. The winding is achieved
with a pair of micro-bobbins. The laser is split into two, the first beam being fixed, and the second movable circularly
around the first. When the bobbins are made into contact with DNA and revolving motion started, the fiber is wound and
suspended between them. The unwinding can be achieved just by reversing the revolving motion.