Dielectrophoretic dynamic light-scattering (DDLS) spectroscopy
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Communicated by James L. Dye, Michigan State University, East Lansing, MI, June 18, 2003 (received for review December 10, 2002)
Abstract
Dielectrophoretic dynamic light-scattering (DDLS) spectroscopy is presented. DDLS identifies macromolecules based on their dielectric, or polarizability, properties. DDLS measurements are carried out in an oscillating, nonuniform electric field. The field induces macromolecules to undergo dielectrophoretic motion, which is detected by the modulation in the dynamic light-scattering autocorrelation function. The DDLS experimental setup, data analysis, and data on latex particles and yeast cells are presented.
Footnotes
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↵ † Present address: Abbott Laboratories, D09N9, AP20, Abbott Park, IL 60064. E-mail: folim.halaka{at}abbott.com.
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Abbreviations: DLS, dynamic light scattering; DDLS, dielectrophoretic DLS; FT, Fourier transform; RF, radio frequency.
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↵ ‡ The terms “particles,” “cells,” “macromolecules,” “particulates,” and “polymers” are used here interchangeably unless otherwise noted.
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↵ § Charges in larger molecules with complicated charge distribution may not neatly rearrange to form a single classical “dipole.” The resultant from the vector addition of all the possible dipoles would represent the dipole meant here.
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↵ ¶ Dielectrophoretic mobility is the dielectrophoretic velocity normalized to units of field strength and field gradient in analogy to electrophoretic mobility.
- Copyright © 2003, The National Academy of Sciences
