Manipulation of Single DNA Molecule inside Capillary

Manipulation of μm-sized particle is one of the important techniques in bioengineering. Recently, the techniques have been applied to conduct DNA manipulation. DNA molecule can be attached on latex particle and the particle can be easily manipulated by laser tweezers. In this paper, the latex-DNA complex was manipulated inside a capillary (inner diameter 1-35μm). Micromanipulation inside the capillary has some advantages, because diffusion of DNA is restricted in one-dimension and the DNA can be easily stretched by suspension flow. Even through these advantages, it is some difficulties because laser focal spot is distorted by the capillary wall, and the distortion reduces trapping force inside the capillary. We designed an optical system to trap the DNA-bead complex inside the capillary and investigated the characteristics of laser trapping inside the capillary. The DNA molecule was also stretched by electric field and/or suspension flow.The conventional DNA sequencing of a long DNA molecule requires a reorganization process. This process is time consuming and requires tremendous efforts, because the long DNA is cut into smaller fragments, which lose information on their order. Utilizing the manipulation techniques of single DNA molecule, we experimentally demonstrated the sample preparation to obtain the fragments with order information. These manipulation techniques will contribute DNA sequencing of the long DNA molecule.