Abstract
We observed single molecules of fluorescently labeled double-stranded (ds) DNA held in an anti-Brownian electrokinetic trap. From the measured density fluctuations we extract the density-density response function of the molecule over times and distances , i.e., how a perturbation in density in one part of the molecule propagates through the rest of the molecule. We find a nonmonotonic radial dependence of the relaxation time. In contrast with earlier measurements on freely diffusing dsDNA, we observe clear signs of internal hydrodynamic interactions.
- Received 19 September 2006
DOI:https://doi.org/10.1103/PhysRevLett.98.116001
©2007 American Physical Society