Applications of a new optical technique for measuring the dielectrophoretic behaviour of micro-organisms

Price, Jonathan A.R.; Burt, Julian P.H.; Pethig, Ronald

doi:10.1016/0304-4165(88)90170-5

Cited by 102 publications

(51 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…9͑a͒ was chosen because it provides a large value for ͑E · ٌ͒E using modest values of applied voltage. 73 The electrode thickness is ϳ70 nm, and the characteristic dimension defining the planar geometry typically ranges from 10 to 120 m, chosen to be 5-10 times the diameter of the particles to be manipulated by DEP. As depicted in Fig.…”

Section: Technologymentioning

confidence: 99%

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

2010

Self Cite

View full text Add to dashboard Cite

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.

show abstract

Section: Technologymentioning

confidence: 99%

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

2010

Self Cite

View full text Add to dashboard Cite

show abstract

“…For living cells, these characteristics are defined by composition, morphology, and phenotype (16,17). Thus, DEP and ROT have been used to study bacteria (18), yeasts (11,19), plant cells (10), and mammalian cells (20,21) and to investigate cellular alterations accompanying physiological changes such as mitotic stimulation (16) and induced differentiation (7,17,21).…”

mentioning

confidence: 99%

Separation of human breast cancer cells from blood by differential dielectric affinity.

Becker

Wang

Huang

et al. 1995

Proc. Natl. Acad. Sci. U.S.A.

646

508

View full text Add to dashboard Cite

Electrorotation measurements were used to demonstrate that the dielectric properties of the metastatic human breast cancer cell line MDA231 were significantly different from those of erythrocytes and T lymphocytes. These dielectric differences were exploited to separate the cancer cells from normal blood cells by appropriately balancing the hydrodynamic and dielectrophoretic forces acting on the cells within a dielectric affinity column containing a microelectrode array. The operational criteria for successful particle separation in such a column are analyzed and our findings indicate that the dielectric affinity technique may prove useful in a wide variety of cell separation and characterization applications.Cell separation has numerous applications in medicine, biotechnology, and research and in environmental settings. For example, the use of autologous bone marrow transplants in the remediation of advanced cancers requires the removal of cancer cells from the patient's marrow (1), the study of signaling between blood cells requires purified cell subpopulations (2), and the purification of contaminated water supplies necessitates elimination of parasites such as Giardia and Cryptosporidium (3,4). Current sorting technologies usually exploit differences in cell density, immunologic targets, or receptor-ligand interactions. These techniques are often inadequate, producing insufficiently pure cell populations, being too slow, or being too limited in the spectrum of target cells. Identification of novel properties by which different cell types may be discerned and of new ways for their selective manipulation are clearly fundamental components for improving sorting methodologies.A particle suspended in a medium of different dielectric characteristics becomes electrically polarized when subjected to an alternating electrical field. Interaction between this induced polarization and the field gives rise to various electrokinetic effects. For example, a spatially inhomogeneous field will exert a lateral dielectrophoretic (DEP) force on the particle, directing it toward the minimum of dielectric potential (5-9), while a rotating field will induce particle electrorotation (ROT; refs. 10-12). The frequency dependencies of the magnitude and direction of these forces are functions of the intrinsic electrical properties of the particle that depend on the particle constitution and structural organization (13-15). For living cells, these characteristics are defined by composition, morphology, and phenotype (16, 17). Thus, DEP and ROT have been used to study bacteria (18), yeasts (11,19), plant cells (10), and mammalian cells (20,21) and to investigate cellular alterations accompanying physiological changes such as mitotic stimulation (16) and induced differentiation (7,17,21 MATERIALS AND METHODS Cells. Peripheral blood was collected by venipuncture into 90 parts Ca2+/Mg2+-free phosphate-buffered saline containing 5 mM hemisodium EDTA to prevent clotting. T lymphocytes were obtained from (human immunodeficiency virusa...

show abstract

“…An optical system was first described by Price et al, (1988) to detect dielectrophoretically trapped bacterial cells by monitoring the changes in light absorbance through the suspension as bacteria collected at an electrode array by pDEP. Later on, Pethig et al (1992) reported a dual beam optical spectrometer with improved sensitivity for the detection of yeast cells collected by both nDEP and pDEP (Talary & Pethig, 1994).…”

Section: Absorbance Based Measurementsmentioning

confidence: 99%

Enhancing the Performance of Surface-based Biosensors by AC Electrokinetic Effects - a Review

Roy¹,

Tomkins²,

Docoslis³

2011

Biosensors - Emerging Materials and Applications

View full text Add to dashboard Cite

Applications of a new optical technique for measuring the dielectrophoretic behaviour of micro-organisms

Cited by 102 publications

References 9 publications

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

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

Separation of human breast cancer cells from blood by differential dielectric affinity.

Enhancing the Performance of Surface-based Biosensors by AC Electrokinetic Effects - a Review

Contact Info

Product

Resources

About