Quantcast

Note: Direct force and ionic-current measurements on DNA in a nanocapillary.

Research paper by O O Otto, L J LJ Steinbock, D W DW Wong, J L JL Gornall, U F UF Keyser

Indexed on: 08 Sep '11Published on: 08 Sep '11Published in: The Review of scientific instruments



Abstract

We have developed optical tweezers, with force measurements based on fast video tracking, for analysis and control of DNA translocation through nanocapillaries. Nanocapillaries are single-molecule biosensors with very similar characteristics to solid-state nanopores. Our novel experimental setup allows for ionic-current measurements in which the nanocapillary is oriented perpendicular to the trapping laser. Using video-based particle tracking, we are able to measure the position of DNA coated colloids at sub-millisecond resolution and in real-time. We present the first electrophoretic force and simultaneous ionic-current measurements of a single DNA molecule inside the orifice of a nanocapillary.