Séminaire exceptionnel – 11 juil. 2017 – 11h salle 250
One-parameter theory for DNA extension in nanochannels
Bernhard Mehlig – Göteborgs Univ.
The extension of DNA during confinement in a nanochannel has attracted substantial attention for next-generation genomics and as a fundamental problem in polymer physics. But recent experiments measuring DNA extension in nanochannels are at odds with even the most basic predictions of current scaling theories for the conformations of confined semiflexible polymers like DNA. We posit that this discrepancy arises because the experimental systems do not satisfy the strong inequalities underlying the existing scaling theory. We develop a new theory, based on the properties of a weakly self-avoiding, one-dimensional telegraph process. Our theory collapses both recent experimental results and simulation data onto a single master curve, as a function of a single parameter that varies continuously throughout the experimentally relevant region of the parameter space. In special cases previous scaling theories are recovered.