Stretching single molecular DNA by temperature gradient

The authors present a method to control the conformation of DNA by using temperature gradient. The conformations of one end tethered and two ends tethered DNA are measured in different temperature gradients up to 3 K/mu m. The results show that temperature gradient can exert force on a single DNA and create internal tension within it. The magnitude of the force is of the order of 0.1 pN and is enough to manipulate and stretch DNA. This way of manipulating DNA requires no beads and provides local control, while none of the other methods can satisfy these two requirements at the same time. (C) 2007 American Institute of Physics.