Inserting and manipulating DNA in a nanopore with optical tweezers.

The translocation of small molecules and polymers is an integral process for the functioning of living cells. Many of the basic physical, chemical, and biological interactions have not yet been studied because they are not directly experimentally accessible. We have shown that a combination of optical tweezers, single solid-state nanopores, and electrophysiological ionic current detection enable deeper insight into the behavior of polymers in confinement. Here we describe the experimental procedures that are necessary to manipulate single biopolymers in a single nanopore, not only by electrical fields, but also through mechanical forces using optical tweezers.