This Article Figures Only Full Text Full Text (PDF) Supporting Information Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a colleague Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Add to My File Cabinet Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via ISI Web of Science (10) Citing Articles via Google Scholar Google Scholar Articles by Moffitt, J. R. Articles by Bustamante, C. Search for Related Content PubMed PubMed Citation Articles by Moffitt, J. R. Articles by Bustamante, C. Social Bookmarking                What's this?

 Previous Article  | Table of Contents |  Next Article 

BIOLOGICAL SCIENCES / BIOPHYSICS
Differential detection of dual traps improves the spatial resolution of optical tweezers

Jeffrey R. Moffitt^*,, Yann R. Chemla^*,, David Izhaky, and Carlos Bustamante^*,,,¶

Departments of *Physics Molecular and Cell Biology and Chemistry and Howard Hughes Medical Institute, University of California, Berkeley, CA 94720

Contributed by Carlos Bustamante, April 25, 2006

The drive toward more sensitive single-molecule manipulation techniques has led to the recent development of optical tweezers capable of resolving the motions of biological systems at the subnanometer level, approaching the fundamental limit set by Brownian fluctuations. One successful approach has been the dual-trap optical tweezers, in which the system of study is held at both ends by microspheres in two separate optical traps. We present here a theoretical description of the Brownian limit on the spatial resolution of such systems and verify these predictions by direct measurement in a Brownian noise-limited dual-trap optical tweezers. We find that by detecting the positions of both trapped microspheres, correlations in their motions can be exploited to maximize the resolving power of the instrument. Remarkably, we show that the spatial resolution of dual optical traps with dual-trap detection is always superior to that of more traditional, single-trap designs, despite the added Brownian noise of the second trapped microsphere.

single molecule | subnanometer resolution | signal-to-noise ratio

Author contributions: C.B. designed research; J.R.M., Y.R.C., and D.I. performed research; J.R.M., Y.R.C., and D.I. analyzed data; and J.R.M. and Y.R.C. wrote the paper.

Conflict of interest statement: No conflicts declared.

^¶To whom correspondence should be addressed. E-mail: carlos{at}alice.berkeley.edu

© 2006 by The National Academy of Sciences of the USA

CiteULike    Complore    Connotea    Del.icio.us    Digg    What's this?

This article has been cited by other articles in HighWire Press-hosted journals:

				A. E. Wallin, A. Salmi, and R. Tuma Step Length Measurement--Theory and Simulation for Tethered Bead Constant-Force Single Molecule Assay Biophys. J., August 1, 2007; 93(3): 795 - 805. [Abstract] [Full Text] [PDF]

				M. Manosas, J.-D. Wen, P. T. X. Li, S. B. Smith, C. Bustamante, I. Tinoco Jr., and F. Ritort Force Unfolding Kinetics of RNA using Optical Tweezers. II. Modeling Experiments Biophys. J., May 1, 2007; 92(9): 3010 - 3021. [Abstract] [Full Text] [PDF]

Current Issue | Archives | Online Submission | Info for Authors | Editorial Board | About Subscribe | Advertise | Contact | Site Map Copyright © 2006 by the National Academy of Sciences