Encyclopedia of Biophysics

Living Edition
| Editors: Gordon Roberts, Anthony Watts, European Biophysical Societies

Anti-Brownian Traps

  • Allison H. Squires
  • Adam E. Cohen
  • W. E. MoernerEmail author
Living reference work entry
DOI: https://doi.org/10.1007/978-3-642-35943-9_486-1



Brownian motion is typically considered an inescapable attribute of small particles in free solution. This random jiggling often impedes or prohibits optical studies of the behavior of nanometer-sized objects, such as single biomolecules, because such objects quickly diffuse away from the observation region. The rate of diffusion increases with decreasing particle size, so the window of opportunity for measuring small particles is very short. Anti-Brownian traps address this challenge by partially suppressing Brownian motion: the position of a single particle is monitored, and active feedback is used to apply forces that directly counteract the observed displacements. This process confines the particle to a small region of interest (ROI), enabling extended study without surface attachment or encapsulation, both of which could perturb the particle’s behavior. A powerful single-molecule method, anti-Brownian traps have been used to...
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Copyright information

© European Biophysical Societies' Association (EBSA) 2018

Authors and Affiliations

  • Allison H. Squires
    • 1
  • Adam E. Cohen
    • 2
  • W. E. Moerner
    • 1
    Email author
  1. 1.Department of ChemistryStanford UniversityStanfordUSA
  2. 2.Departments of Chemistry and Chemical Biology and PhysicsHarvard UniversityCambridgeUSA

Section editors and affiliations

  • Nils G. Walter
    • 1
  1. 1.Department of ChemistryThe University of MichiganAnn ArborUSA