Physical Society Colloquium

Nanopore DNA Sequencing: Erwin Schrödinger knew how to do it 100 years ago before he played with his famous “cat”

Xinsheng Sean Ling

Department of Physics
Brown University

The idea of using ionic current through a small pore as a DNA sequencing mechanism was appealing and deceitfully simple. All one has to do is to measure how the current varies as a function of time while a single stranded DNA is driven through by electric field. Comparing to the massive amount of effort using DNA polymerase and expensive optics, this polymerase-free approach drew lots of attention from physicists: is it physically possible to resolve DNA bases spaced at 0.4nm apart and with minute differences in their atomic composition? It turns out, after two decades of trying, it became clear that it is indeed possible, the physics was there all along, in Schrödinger's 1915 paper in fact, ten years before he invented the Schrödinger equation (its solutions imply a “cat” can be both dead and alive at the same time). I will discuss the current effort in building such a machine based on Schrödinger's first-passage time theory and the principle of kinetic proofreading by Hopfield and Ninio.