[Sequencing of DNA by mechanical opening of the double helix: a theoretical evaluation]

We propose and evaluate a model experiment, in which the sequence of a DNA fragment is determined by mechanically opening the double helix in a controlled manner (e.g. pulling on the 3' end of one strand), and measuring the variation of the force exerted by the base pairs on a nanodynamometer (e.g. on a bead in an optical trap or a glass microneedle attached to the 5' end of the other strand). We show that the major limitation of the approach is the longitudinal elasticity of the already sequenced single strand sections, which soften the displacement-force function, and facilitate spontaneous thermal opening of the base pairs.