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Hughes MP, Clarke KSP, Hoque R, Griffiths OV, Kruchek EJ, Bertagna F, Jeevaratnam K, Lewis R, Labeed FH. On the low-frequency dispersion observed in dielectrophoresis spectra. Electrophoresis 2024. [PMID: 38193244 DOI: 10.1002/elps.202300211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 12/16/2023] [Accepted: 12/19/2023] [Indexed: 01/10/2024]
Abstract
The foundation of dielectrophoresis (DEP) as a tool for biological investigation is the use of the Clausius-Mossotti (C-M) factor to model the observed behaviour of cells experiencing DEP across a frequency range. Nevertheless, it is also the case that at lower frequencies, the DEP spectrum deviates from predictions; there exists a rise in DEP polarisability, which varies in frequency and magnitude with different cell types and medium conductivities. In order to evaluate the origin of this effect, we have studied DEP spectra from five cell types (erythrocytes, platelets, neurons, HeLa cancer cells and monocytes) in several conditions including medium conductivity and cell treatment. Our results suggest the effect manifests as a low-pass dispersion whose cut-off frequency varies with membrane conductance and capacitance as determined using the DEP spectrum; the effect also varies as a logarithm of medium conductivity and Debye length. These together suggest that the values of membrane capacitance and conductance depend not only on the impedance of the membrane itself, but also of the surrounding double layer. The amplitude of the effect in different cell types compared to the C-M factor was found to correlate with the depolarisation factors for the cells' shapes, suggesting that this ratio may be useful as an indicator of cell shape for DEP modelling.
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Affiliation(s)
- Michael Pycraft Hughes
- Department of Biomedical Engineering and Biotechnology, Khalifa University, Abu Dhabi, UAE
- Centre for Biomedical Engineering, University of Surrey, Guildford, Surrey, UK
| | - Krista S P Clarke
- Centre for Biomedical Engineering, University of Surrey, Guildford, Surrey, UK
| | - Rashedul Hoque
- Centre for Biomedical Engineering, University of Surrey, Guildford, Surrey, UK
| | | | - Emily J Kruchek
- Centre for Biomedical Engineering, University of Surrey, Guildford, Surrey, UK
| | - Federico Bertagna
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, University of Surrey, Guildford, Surrey, UK
| | - Kamalan Jeevaratnam
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, University of Surrey, Guildford, Surrey, UK
| | - Rebecca Lewis
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, University of Surrey, Guildford, Surrey, UK
| | - Fatima H Labeed
- Centre for Biomedical Engineering, University of Surrey, Guildford, Surrey, UK
- Department of Biology, UAEU University, Al Ain, UAE
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Merla C, Liberti M, Apollonio F, d'Inzeo G. Quantitative assessment of dielectric parameters for membrane lipid bi-layers from RF permittivity measurements. Bioelectromagnetics 2009; 30:286-98. [DOI: 10.1002/bem.20476] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Sekine K, Hibino C, Kimura M, Asami K. Effects of T-tubules on dielectric spectra of skeletal muscle simulated by boundary element method with two-dimensional models. Bioelectrochemistry 2007; 70:532-41. [DOI: 10.1016/j.bioelechem.2007.01.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2006] [Revised: 11/11/2006] [Accepted: 01/10/2007] [Indexed: 10/23/2022]
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