Confinement and Manipulation of Actin Filaments by Electric Fields
Mark E. Arsenault 1, Hui Zhao 1, Prashant K. Purohit 1, Yale E. Goldman 2 and Haim H. Bau 1*
1 University of Pennsylvania
2 Univ. of Pennsylvania School of Med.
* To whom correspondence should be addressed. E-mail: bau{at}seas.upenn.edu.
Submitted on June 8, 2007
Revised on July 6, 2007
Accepted on 9 August 2007
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Abstract |
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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.
Key Words:
actin, brownian, conductivity, dielectrophoresis, electric-field, manipulation
