Departmental Papers (MEAM)

Document Type

Journal Article

Date of this Version

August 2007


Postprint version. Published in Biophysical Journal, Volume 93, August 2007, pages L42-L44.
Publisher URL:


When an AC electric field was applied across a small gap between two metal electrodes elevated above a surface, rhodamine-phalloidin-labeled actin filaments were attracted to the gap and became suspended between the two electrodes. The variance <s²(x)> of each filament's horizontal, lateral displacement was measured as a function of electric field intensity and position along the filament. <s²(x)> markedly decreased as the electric field intensity increased. Hypothesizing that the electric field induces tension in the filament, we estimated the tension using a linear, Brownian dynamic model. Our experimental method provides a novel means for trapping and manipulating biological filaments and for probing the surface conductance and mechanical properties of single polymers.



Date Posted: 16 November 2007

This document has been peer reviewed.