Internal mechanical response of a polymer in solution.
We observed single molecules of fluorescently labeled double-stranded (ds) lambda 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 >4.5 ms and distances >250 nm, 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.
Cohen
Adam E
AE
Department of Physics, Stanford University, Stanford, California 94305, USA. acohen@post.harvard.edu
Moerner
W E
WE
D004279:DNA, Viral / Q000737:chemistry*; D004563:Electrochemistry; D005456:Fluorescent Dyes / Q000737:chemistry; D007700:Kinetics; D009690:Nucleic Acid Conformation; D012542:Scattering, Radiation; D012996:Solutions
D004279:DNA, Viral; D005456:Fluorescent Dyes; D012996:Solutions