'Sewing Machine' Manipulates DNA Molecule

This ain't your grandmother's sewing machine. Using a single DNA molecule as thread, researchers in Japan designed microhooks and microbobbins to form a "sewing machine" to manipulate DNA. Chromosomal DNA molecules are used in hybridization, protein binding, and epigenetics experiments. Because a chromosomal DNA double helix is only 2 nm in diameter, with a length ranging from millimeters to centimeters, the molecule easily breaks from hydrodynamic shear. To prevent this breakage, the research team, led by Kyohei Terao at Kyoto University, designed microscopic tools to move and direct the DNA (Lab Chip, DOI: 10.1039/b803753a). The tools, created via photolithography, consist of a Z-shaped microhook to catch the DNA and a microbobbin, around which the DNA is wrapped. Using laser methods to manipulate the microtools, Terao and colleagues captured and separated pairs of DNA helices with the microhook. Terao's group also wrapped and unwrapped the DNA from two microbobbins. These tools, the researchers say, will allow the use of large DNA molecules in genetics studies and biochemical assays.