Dielectrophoretic studies of the activation of human T lymphocytes using a newly developed cell profiling system

Pethig, Ronald; Bressler, Vincent; Carswell-Crumpton, Catherine; Chen, Yan; Foster-Haje, Linda; García‐Ojeda, Marcos E.; Lee, Richard S.; Lock, Gary M.; Talary, Mark S.; Tate, Keri

doi:10.1002/1522-2683(200207)23:13<2057::aid-elps2057>3.0.co;2-x

Cited by 83 publications

(54 citation statements)

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“…We measured the average Jurkat cell radius to be 5.2 lm. This is smaller than the radius of 7-8 lm reported by other groups [20] but agrees well with the radius of 5.18 lm obtained by another group [21]. Smaller cells could appear for a number of reasons, such as cell culture contamination or state in the cell cycle.…”

Section: Methodssupporting

confidence: 90%

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Ultrashort electric pulse induced changes in cellular dielectric properties

Garner

Chen

et al. 2007

Biochemical and Biophysical Research Communications

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The interaction of nanosecond duration pulsed electric fields (nsPEFs) with biological cells, and the models describing this behavior, depend critically on the electrical properties of the cells being pulsed. Here, we used time domain dielectric spectroscopy to measure the dielectric properties of Jurkat cells, a malignant human T-cell line, before and after exposure to five 10 ns, 150 kV/cm electrical pulses. The cytoplasm and nucleoplasm conductivities decreased dramatically following pulsing, corresponding to previously observed rises in cell suspension conductivity. This suggests that electropermeabilization occurred, resulting in ion transport from the cell's interior to the exterior. A delayed decrease in cell membrane conductivity after the nsPEFs possibly suggests long-term ion channel damage or use dependence due to repeated membrane charging and discharging. This data could be used in models describing the phenomena at work. Ó 2007 Elsevier Inc. All rights reserved.Keywords: Dielectric spectroscopy; Nanosecond pulsed electric fields; Electroporation; Permeabilization; Plasma membrane; Time domain; Intracellular manipulation; Ultrashort pulsesThe permeability of the cell membrane to external molecules can be dramatically increased by applying pulsed electric fields (PEFs) above a threshold voltage [1]. The mechanism behind this electropermeabilization is electroporation, or pore formation in the cell membrane, and usually occurs for PEFs with electric fields on the order of a few kV/cm and pulse durations on the order of 0.1-10 ms. With the appropriate combination of these parameters, electroporation is irreversible and the membrane breaks down, which is desirable for applications ranging from bacterial decontamination to food processing [2]. Many applications require temporarily opening the cell membrane to normally impermeant molecules, such as electrochemotherapy and gene therapy [3]. Applying pulses with higher field strength (50-300 kV/cm) and shorter duration (10-300 ns) do not fully charge the cell membrane and instead interact primarily with the membranes of intracellular organelles [4]. These nanosecond duration PEFs (nsPEFs) cause intracellular calcium release [5,6] and apoptosis-induction in cell suspensions and in vivo tumors [5,7,8]. To better understand the mechanisms involved, attempts to develop mathematical models are underway 0006-291X/$ -see front matter Ó

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Section: Methodssupporting

confidence: 90%

“…The typical value for the isotonic C m of Jurkat cells is approximately 14 mF/m 2 [20]. However, our measurements are within the typical range for T cells, which Pethig et al lists as 6-15 mF/m 2 [21].…”

Section: Discussionsupporting

confidence: 63%

Ultrashort electric pulse induced changes in cellular dielectric properties

Garner

Chen

et al. 2007

Biochemical and Biophysical Research Communications

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“…This condition is readily satisfied by taking DEP measurements on cells located nearer to the quadrupole electrode edges than to the central location. 42,43 The importance of higher-order moments was also found to apply to azimuthally periodic electrode structures used to achieve passive DEP levitation of particles, where a pronounced size-dependent effect not anticipated by the conventional dipole-based theory was observed. 44,45 Higher-order moments are responsible for the levitation force achieved by such electrode structures because the electric field is zero along the central axis and so the induced dipole moment is zero.…”

Section: B Refining the Induced Dipole Approximationmentioning

confidence: 98%

“…87 Methods other than photographic recording through a microscope have been developed to measure the DEP collection of particles at electrodes. This can be achieved by monitoring changes in the optical scattering of light beams through particle suspensions, 88 by computerized image analysis of particle motion, 42,89 and by measuring changes of the impedance of the electrodes. 90,91 More recently, fluorescence spectroscopy has been used to measure the DEP collection of submicron particles.…”

Section: Technologymentioning

confidence: 99%

Review Article—Dielectrophoresis: Status of the theory, technology, and applications

2010

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A review is presented of the present status of the theory, the developed technology and the current applications of dielectrophoresis ͑DEP͒. Over the past 10 years around 2000 publications have addressed these three aspects, and current trends suggest that the theory and technology have matured sufficiently for most effort to now be directed towards applying DEP to unmet needs in such areas as biosensors, cell therapeutics, drug discovery, medical diagnostics, microfluidics, nanoassembly, and particle filtration. The dipole approximation to describe the DEP force acting on a particle subjected to a nonuniform electric field has evolved to include multipole contributions, the perturbing effects arising from interactions with other cells and boundary surfaces, and the influence of electrical double-layer polarizations that must be considered for nanoparticles. Theoretical modelling of the electric field gradients generated by different electrode designs has also reached an advanced state. Advances in the technology include the development of sophisticated electrode designs, along with the introduction of new materials ͑e.g., silicone polymers, dry film resist͒ and methods for fabricating the electrodes and microfluidics of DEP devices ͑photo and electron beam lithography, laser ablation, thin film techniques, CMOS technology͒. Around three-quarters of the 300 or so scientific publications now being published each year on DEP are directed towards practical applications, and this is matched with an increasing number of patent applications. A summary of the US patents granted since January 2005 is given, along with an outline of the small number of perceived industrial applications ͑e.g., mineral separation, micropolishing, manipulation and dispensing of fluid droplets, manipulation and assembly of micro components͒. The technology has also advanced sufficiently for DEP to be used as a tool to manipulate nanoparticles ͑e.g., carbon nanotubes, nano wires, gold and metal oxide nanoparticles͒ for the fabrication of devices and sensors. Most efforts are now being directed towards biomedical applications, such as the spatial manipulation and selective separation/enrichment of target cells or bacteria, high-throughput molecular screening, biosensors, immunoassays, and the artificial engineering of three-dimensional cell constructs. DEP is able to manipulate and sort cells without the need for biochemical labels or other bioengineered tags, and without contact to any surfaces. This opens up potentially important applications of DEP as a tool to address an unmet need in stem cell research and therapy.

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“…This approximation has been used in the DEP and ER studies of cell apoptosis, [22][23][24] as well as for studies of induced cell differentiation and activation, 19,25,26 for example. In summary, the state-of-art theory and method in the current literature for deriving cell dielectric properties from the peak frequency measurement of ER and the crossover frequency measurement of DEP are based on two physical reasons: (1) the definitions of peak and crossover frequencies, which are associated with the Maxwell-Wagner phenomenon and (2) the low frequency (DC) limits for representing the effective cell permittivity and conductivity.…”

Section: Introductionmentioning

confidence: 99%

Refinement of the theory for extracting cell dielectric properties from dielectrophoresis and electrorotation experiments

2011

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A modified theory is proposed for extracting cell dielectric properties from the peak frequency measurement of electrorotation (ER) and the crossover frequency measurement of dielectrophoresis (DEP). Current theory in the literature is based on the low frequency (DC) approximations for the equivalent cell permittivity and conductivity, which are valid when the measurements are performed in a medium with conductivity less than 1 mS=m. The present theory extracts the cell properties through optimizing an expression for the medium conductivity in terms of the peak ER, or DEP crossover, frequency according to its definition using full expressions of equivalent cell permittivity and conductivity. Various levels of approximation of the theory are proposed and discussed through a scaling analysis. The present theory can extract both membrane and interior properties from the low and the high peak ER, or DEP crossover, frequencies for any medium conductivity provided the peak ER, or DEP crossover, frequency exists. It can be reduced to the linear theory for the low peak ER and DEP crossover frequencies in the literature when the medium conductivity is less than 10 mS=m. However, we can determine the membrane capacitance and conductance via the slope and intercept, respectively, of the straight line fitting of the ER peak and DEP frequency against medium conductivity data according to the linear theory only when the intercept dominates the experimental uncertainty, which occurs when the medium conductivity is less than 1 mS=m in practice.

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Dielectrophoretic studies of the activation of human T lymphocytes using a newly developed cell profiling system

Cited by 83 publications

References 18 publications

Ultrashort electric pulse induced changes in cellular dielectric properties

Ultrashort electric pulse induced changes in cellular dielectric properties

Review Article—Dielectrophoresis: Status of the theory, technology, and applications

Refinement of the theory for extracting cell dielectric properties from dielectrophoresis and electrorotation experiments

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