Date of this Version
The Journal of Physical Chemistry Part B
The tethered particle motion (TPM) technique involves an analysis of the Brownian motion of a bead tethered to a slide by a single DNA molecule. We describe an improved experimental protocol with which to form the tethers, an algorithm for analyzing bead motion visualized using differential interference contrast microscopy, and a physical model with which we have successfully simulated such DNA tethers. Both experiment and theory show that the statistics of the bead motion are quite different from those of a free semiflexible polymer. Our experimental data for chain extension versus tether length fit our model over a range of tether lengths from 109 to 3477 base pairs, using a value for the DNA persistence length that is consistent with those obtained under similar solution conditions by other methods. Moreover, we present the first experimental determination of the full probability distribution function of bead displacements and find excellent agreement with our theoretical prediction. Our results show that TPM is a useful tool for monitoring large conformational changes such as DNA looping.
This document is the unedited Author’s version of a Submitted Work that was subsequently accepted for publication in The Journal of Physical Chemistry B, copyright © 2006 American Chemical Society after peer review.
Nelson, P. C., Zurla, C., Brogioli, D., Beausang, J. F., Finzi, L., & Dunlap, D. (2006). Tethered Particle Motion as a Diagnostic of DNA Tether Length. The Journal of Physical Chemistry Part B, 110 (24), 17260-17267. http://dx.doi.org/10.1021/jp0630673
Date Posted: 01 May 2017
This document has been peer reviewed.