Application of local temperature control for DNA micromanipulation

Manipulation of a single DNA molecule would support analysis of genomic DNA. We have been developing opto-electrostatic micro-manipulation which used laser trapping and an electrostatic force. Laser trapping of a DNA molecule, however, is impossible, and we have to attach a latex bead to one end of a DNA molecule to conduct the manipulation. In this paper, we propose a novel non-contact manipulation method for DNA molecules. This new method, named local area melting micro manipulation (LMMM), is based on the property of solution that excludes impurities in the solid phase. A single DNA molecule was confined in a molten small area produced by YAG laser irradiation, and the molten area at the laser focus was traversed so that DNA molecules could be transported. This method can also be applied in regulation of enzymatic reaction in a limited local area. The possibility of DNA ligation on a microscope field was demonstrated.