Department of Physics Papers

Document Type

Working Paper

Date of this Version

3-2006

Publication Source

Physical Review Letters

Volume

96

Issue

8

Start Page

1

Last Page

4

DOI

10.1103/PhysRevLett.96.088306

Abstract

The tethered-particle method is a single-molecule technique that has been used to explore the dynamics of a variety of macromolecules of biological interest. We give a theoretical analysis of the particle motions in such experiments. Our analysis reveals that the proximity of the tethered bead to a nearby surface (the microscope slide) gives rise to a volume-exclusion effect, resulting in an entropic force on the molecule. This force stretches the molecule, changing its statistical properties. In particular, the proximity of bead and surface brings about intriguing scaling relations between key observables (statistical moments of the bead) and parameters such as the bead size and contour length of the molecule. We present both approximate analytic solutions and numerical results for these effects in both flexible and semiflexible tethers. Finally, our results give a precise, experimentally-testable prediction for the probability distribution of the distance between the polymer attachment point and the center of the mobile bead.

Included in

Physics Commons

Share

COinS
 

Date Posted: 07 April 2017

This document has been peer reviewed.