Analytical Characteristic of Chromatography Device Using Dielectrophoresis Phenomenon

This paper reports the separation of cells using a dielectrophoretic (DEP) chromatography device. The device consists of a micro channel and an array of interdigitated microelectrodes on a glass substrate. The sample cells were fed pulse-wise into the carrier flow using a micro-injector. The cells in the sample received a non-uniform electric field made with an electrode array. The direction of DEP motion is towards the higher field when the cell is more polarizable than the medium (positive DEP), while the direction is towards the lower field when the cell is less polarizable than the medium (negative DEP). Therefore, the cell separation depends on the size and dielectric characteristic. The effects of carrier flow rate, frequency, applied voltage, and sweep frequency on the retention time of the sample in the device were examined. In this study, mouse-hybridoma 3-2H3 cells and yeast cells were used as the sample cell. The analytical characteristic of the DEP chromatography device was evaluated according to the difference of retention time by the electric field. As a result, the separation in the cells in the negative DEP using the DEP chromatography was found to be effective. In addition, the effect of the sweep frequency on the difference in the retention time of the mouse hybridoma 3-2H3 cells and the yeast cells was very large. Consequently, the effectiveness of the DEP chromatography device was proven.

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Development of Particle Packed Bed Type Chromatography Using Dielectrophoresis

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.534.88 ◽

2013 ◽

Vol 534 ◽

pp. 88-92 ◽

Cited By ~ 1

Author(s):

Yusuke Umezawa ◽

Okihisa Kobayashi ◽

Syoji Kanai ◽

Masaru Hakoda

Keyword(s):

Cell Suspension ◽

Retention Time ◽

Packed Bed ◽

Time Difference ◽

Analytical Characteristic ◽

Carrier Flow ◽

Absorption Spectrometer

In this study, we analyzed differences in cell species using dielectrophoresis (DEP) and propose a particle packed bed type chromatography device using DEP. Mouse-hybridoma 3-2H3 cells were used as the sample cells. The 3-2H3 cell suspension was fed pulse-wise to a carrier flow and the sample was measured by an absorption spectrometer. The analytical characteristic of chromatography using DEP was evaluated by the retention time difference. We examined the effects of the diameter of packed particles on the retention time difference. The retention time difference in the case of the packed particles of 100 μm diameter was larger than that of 500 μm, which suggests that packed particles of smaller diameter are suitable for analysis using DEP chromatography.

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The effect of surface-charge convection on the settling velocity of spherical drops in a uniform electric field

Journal of Fluid Mechanics ◽

10.1017/jfm.2016.286 ◽

2016 ◽

Vol 797 ◽

pp. 536-548 ◽

Cited By ~ 13

Author(s):

Ehud Yariv ◽

Yaniv Almog

Keyword(s):

Difference Equation ◽

Electric Field ◽

Surface Charge ◽

Settling Velocity ◽

Numerical Solutions ◽

Weak Field ◽

Uniform Electric Field ◽

Electrostatic Problem ◽

Settling Speed ◽

The Difference

The mechanism of surface-charge convection, quantified by the electric Reynolds number $Re$, renders the Melcher–Taylor electrohydrodynamic model inherently nonlinear, with the electrostatic problem coupled to the flow. Because of this nonlinear coupling, the settling speed of a drop under a uniform electric field differs from that in its absence. This difference was calculated by Xu & Homsy (J. Fluid Mech., vol. 564, 2006, pp. 395–414) assuming small $Re$. We here address the same problem using a different route, considering the case where the applied electric field is weak in the sense that the magnitude of the associated electrohydrodynamic velocity is small compared with the settling velocity. As convection is determined at leading order by the well-known flow associated with pure settling, the electrostatic problem becomes linear for arbitrary value of $Re$. The electrohydrodynamic correction to the settling speed is then provided as a linear functional of the electric-stress distribution associated with that problem. Calculation of the settling speed eventually amounts to the solution of a difference equation governing the respective coefficients in a spherical harmonics expansion of the electric potential. It is shown that, despite the present weak-field assumption, our model reproduces the small-$Re$ approximation of Xu and Homsy as a particular case. For finite $Re$, inspection of the difference equation reveals a singularity at the critical $Re$-value $4S(1+R)(1+M)/(1+S)M$, wherein $R$, $S$ and $M$ respectively denote the ratios of resistivity, permittivity and viscosity values in the suspending and drop phases, as defined by Melcher & Taylor (Annu. Rev. Fluid Mech., vol. 1, 1969, pp. 111–146). Straightforward numerical solutions of this equation for electric Reynolds numbers smaller than the critical value reveal a non-monotonic dependence of the settling speed upon the electric field magnitude, including a transition from velocity enhancement to velocity decrement.

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The Electric Field Analysis of Interdigitated Electrode-Array Based on Semi-Analytical Method

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.562-565.1218 ◽

2013 ◽

Vol 562-565 ◽

pp. 1218-1223

Author(s):

Jing Tan ◽

Zhen Fang ◽

Yong Hong Liu ◽

Zhan Zhao

Keyword(s):

Electric Field ◽

Field Distribution ◽

Analytical Method ◽

Electric Field Distribution ◽

Electrode Array ◽

Field Analysis ◽

Uniform Electric Field ◽

Interdigitated Electrode ◽

Theoretical Simulation ◽

Interdigitated Electrode Array

Dielectrophoresis (DEP) is the action of polarizable particles in non-uniform electric field, which depends on the structure of electrode. In this paper, we present a semi-analytical method, on which the electric field distribution by interdigitated electrode-array with battlement structure is considered. According to the congregational conformation of latex micro-beads which subject to the negative dielectrophoresis movement, the potential-trap by interdigitated electrodes is observed experimentally. The result shows that the theoretical simulation result conforms to actual electric field distribution well. It is proved that semi-analytical method exerts power for the research of dielectrophoresis effectively.

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Isoconductivity method to study adhesion of yeast cells to gold electrode

Journal of Electrical Bioimpedance ◽

10.5617/jeb.809 ◽

2019 ◽

Vol 5 (1) ◽

pp. 40-47 ◽

Cited By ~ 3

Author(s):

Gabriel A. Ruiz ◽

Martín L. Zamora ◽

Carmelo J. Felice

Keyword(s):

Strong Dependence ◽

Yeast Cells ◽

Uniform Electric Field ◽

Electrode Impedance ◽

Surface Charges ◽

Electrolyte Interface ◽

Base Solution ◽

Double Layer Capacity ◽

In Series ◽

The Difference

AbstractIn this paper, we used impedance spectroscopy and gold electrodes to detect the presence of yeast cells and monitor the attachment of these cells to the electrodes. We analyzed the effect of conductivity changes of the medium and the attachment on the electrode-electrolyte interface impedance. A three-electrode cell was designed to produce a uniform electric field distribution on the working electrode and to minimize the counter electrode impedance. Moreover, we used a small AC overpotential (10 mV) to keep the system within the linear impedance limits of the electrode-electrolyte interface. This study proposes a new method to differentiate the impedance changes due to the attachment of yeast cells from those due to conductivity changes of the medium. The experiments showed that when the difference between the cell suspension and base solution conductivities is within the experimental error, the impedance changes are only due to the attachment of yeast cells to the electrodes. The experiments also showed a strong dependence (decrease) of the parallel capacity of the electrode electrolyte interface with the yeast cell concentration of suspension. We suggest that this decrease is due to an asymmetrical redistribution of surface charges on both sides of cell, which can be modeled as a biologic capacity connected in series with the double layer capacity of the interface. Our results could help to explain the rate of biofilm formation through the determination of the rate of cell adhesion.

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Dielectrophoretic Rotation in Budding Yeast Cells

Zeitschrift für Naturforschung C ◽

10.1515/znc-1980-11-1245 ◽

1980 ◽

Vol 35 (11-12) ◽

pp. 1111-1113 ◽

Cited By ~ 18

Author(s):

Maja Mischel ◽

Ingolf Lamprecht

Keyword(s):

Field Strength ◽

Electric Field ◽

Budding Yeast ◽

Low Frequency ◽

Rotation Frequency ◽

Moment Of Inertia ◽

Yeast Cells ◽

Uniform Electric Field ◽

The Moment

Abstract Rotation of budding yeast cells in an alternating non-uniform electric field of low frequency was investigated. Rotation frequency was found to be proportional to field strength above a threshold, and varied from cell to cell. The threshold is inversely correlated with the moment of inertia of the cells, while the slope of rotation frequency versus field strength increases with the moment. Rotation frequencies varied between 1 and 10 cycles per second. Clear differences between the dielectrophoretic behaviour of living and heat-inactivated yeast cells were observed.

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