Synopsis: Entangled in tubes

Synopsis Image
Illustration: B. Wang et al., Phys. Rev. Lett. (2010)

Confining Potential when a Biopolymer Filament Reptates

Bo Wang, Juan Guan, Stephen M. Anthony, Sung Chul Bae, Kenneth S. Schweizer, and Steve Granick

Published March 16, 2010

Despite considerable theoretical work, experiments on long chain macromolecules—the diffusion properties of which determine how substances ranging from plastics to cell cytoskeletons behave—have been hard to come by.

In a paper appearing in Physical Review Letters, Bo Wang and colleagues at the University of Illinois in Urbana, US, present measurements of the Brownian motion of molecules that are confined by a harmonic potential to a tubelike region. With single-molecule fluorescence microscopy, they are able to track molecules on polymer networks. They find a surprisingly large regime where the restoring force on a polymer is independent of its displacement. Though their work does not address local space- and time-dependent characteristics of these polymers, they hope that others will look more closely at how distributions, as opposed to more smeared out “averages,” play an important role. – Sami Mitra

Article Options

Subject Areas

New in Physics