抄録
We have been developing a new method of gene mapping of single chromosomal DNA molecules using magnetic beads. The method includes hybridization of probe DNA to the chromosomal DNA attached to a magnetic beads, purification of the hybridized DNA by a magnet, and elongation of the hybridized molecules using a small magnet controlled by a micromanipulator in existence of 0.1% sodium dodecyl sulfate (SDS). Here, we describe a micromanipulation system using magnetic field for elongation and length measurement of a single DNA molecule. The results in our preliminary experiments suggest usefulness of the systems for gene mapping.