Extension of a DNA Molecule by Local Heating with a Laser

Abstract

Thermal convection and thermophoresis induced by mum-scale local heating are shown to elongate a single DNA molecule. An infrared laser used as a point heat source is converged into a dispersion solution of DNA molecules, which is observed under a fluorescent microscope. The thermal convection around the laser focus manifests as extensional flow for the long DNA chain. A simulation of thermal convection that reproduces the experimental condition provides numerical support for the stretching caused by thermal convection. This DNA elongation technique is a novel method for manipulating the intact single DNA molecules, and it can be applied to a "lab on a chip".

Beyond Gel Electrophoresis: Microfluidic Separations, Fluorescence Burst Analysis, and DNA Stretching

“…695 Thermophoretic flows are driven by temperature gradients in a fluid. When a laser locally heats the fluid near a DNA molecule, the chain stretches around 35% to 45%.…”

DNA molecule stretching through thermo-electrophoresis and thermal convection in a heated converging-diverging microchannel

“…Recently, Ichikawa et al [4] have presented a novel DNA extension technique via laser heating. They proved that the new stretching technique was promising and could work in selected applications.…”

Heat guiding and focusing using ballistic phonon transport in phononic nanostructures

“…Once control over directionality is achieved, the possibility to guide and locally apply heat without dissipation can be used in biomedicine15161718, thermoelectrics19, phase-change material technology2021, chemical reaction control22 and virtually wherever wireless nano-heaters are required.…”