Advances in Dielectrophoresis As a Biotechnology Tool

Monday, 6 October 2014: 11:00
Sunrise, 2nd Floor, Galactic Ballroom 8 (Moon Palace Resort)
R. Pethig (University of Edinburgh)
Dielectrophoresis (DEP) has been widely studied for its potential as a biomarker-free method of sorting cells based on their intrinsic dielectric properties. Under appropriate experimental conditions the DEP frequency spectrum typically exhibited by a viable mammalian cell in suspension is characterised by two frequencies, fxo1 and fxo2. At these two characteristic frequencies the effective conductance and capacitance values of the cell exactly match those of the fluid it has displaced, and are commonly known as the DEP cross-over frequencies. At low frequencies (< 10 kHz) viable cells typically exhibit negative DEP and move away from electrodes, with the transition to positive DEP occurring at fxo1 - where the cells move towards high field regions at the electrodes. A transition back to negative DEP occurs at fxo2 (~150 MHz). The dielectric properties of the cell membrane and cell interior can be evaluated from knowledge of the dielectric properties of the suspending fluid, and changes of the physico-chemical properties of the suspending fluid can be used to control the frequencies fxo1 and fxo2

Theoretical and experimental evaluations of fxo1 have been extensive and exploited in practical applications of DEP [1-5]. The current status of this, both in research and commercial exploitation, will be reviewed in this presentation. The factors that control the high frequency DEP cross-over at fxo2 are now under investigation. The status of the ‘exploration of this 2nd frontier of DEP research’ will be described. 

1. Pethig, R. Review Article - Dielectrophoresis: Status of the theory, technology, and applications. Biomicrofluidics  4, 022811 (2010).

2. Pethig, R.; Menachery, A.; Pells, S.; de Sousa, P. Dielectrophoresis: A review of applications for stem cell research. J. Biomed. Biotechnol., e182581 (2010).

3. Gagnon, Z.R. Cellular dielectrophoresis: Applications to the characterization, manipulation, separation and patterning of cells. Electrophoresis 32: 2466-2487 (2011).

4. Pethig, R. Dielectrophoresis: An assessment of its potential to aid the research and practice of drug discovery and delivery. Adv. Drug Deliv. Rev. 65: 1589-1599 (2013).

5. Gascoyne, P.R.C. and Shim, S. Isolation of circulating tumor cells by dielectro-phoresis, Cancers 6: 545-579 (2014).