Forcing DNA and RNA through Artifical Nanopores

Biological molecules can be forced to pass through an aperture in a thin membrane of only several nanometres in diameter (a nanopore). Under the right experimental conditions, the molecules will induce a change in an ionic current flowing through the nanopore. Here, we exploit this principle to detect individual molecules of DNA and RNA and study their structural properties such as diameter and charge density. We study the translocation behaviour of these molecules in nanopores with diameters as small as the cross-sectional diameter of a single DNA molecule. In addition, we use optical tweezers to arrest the molecules inside a nanopore and locally measure and apply forces, which may ultimately be exploited for the controlled detection of local structure along a single biological molecule