Dielectrophoresis (DEP)-Based Electrical Cell Sorting
Materials Required
Principle
Dielectrophoresis-based electrical cell sorting separates suspended cells by the motion generated when polarizable cells experience a non-uniform electric field; cell trajectory depends on cell size, medium conductivity, applied AC frequency, electric-field gradient, and cell dielectric properties, so cells with different DEP responses can be routed, trapped, levitated, or released without biochemical labeling[1][2]. In practical DEP sorters, the readout is the spatial redistribution of cells into different outlets, traps, or recovered fractions; reported examples include DEP field-flow fractionation of leukocytes, breast cancer cells, CD34+ cells, and blood cells, continuous-flow hMSC/osteoblast sorting, and image-based single-cell recovery after DEP manipulation[1][2][12].
MCE has not independently verified the accuracy of these methods. They are for reference only.
Experimental Materials
• Use a low-conductivity DEP-compatible suspension medium because DEP force and heating behavior depend on medium conductivity, and published protocols optimize separation by adjusting buffer composition and conductivity rather than assuming one universal buffer[1][3][4][11].
• Use the target cell suspension and, where validation is needed, a defined mixed population such as hMSCs with osteoblasts, Jurkat cells, bacterial/eukaryotic mixtures, live/dead leukemia cells, platelets with blood cells, or cancer-cell mixtures, because these are the systems directly demonstrated in published DEP sorting studies[2][3][4][6][9][11].
• No antibody is required for label-free DEP sorting, but fluorescence or image-based identification can be used when the published workflow requires cell identity confirmation, rare-cell selection, or post-sort purity assessment, as shown in DEPArray and marker-specific DEP sorting studies[5][12].
• Use a DEP microfluidic device containing patterned electrodes, insulating structures, or contactless-electrode chambers, connected to an AC signal generator or voltage source, syringe pump or pressure-driven flow controller, microscope or imaging system, and collection outlets, because these elements are common to published continuous-flow, contactless, and image-based DEP sorting workflows[2][3][6][7][12].
• Use the target cell suspension and, where validation is needed, a defined mixed population such as hMSCs with osteoblasts, Jurkat cells, bacterial/eukaryotic mixtures, live/dead leukemia cells, platelets with blood cells, or cancer-cell mixtures, because these are the systems directly demonstrated in published DEP sorting studies[2][3][4][6][9][11].
• No antibody is required for label-free DEP sorting, but fluorescence or image-based identification can be used when the published workflow requires cell identity confirmation, rare-cell selection, or post-sort purity assessment, as shown in DEPArray and marker-specific DEP sorting studies[5][12].
• Use a DEP microfluidic device containing patterned electrodes, insulating structures, or contactless-electrode chambers, connected to an AC signal generator or voltage source, syringe pump or pressure-driven flow controller, microscope or imaging system, and collection outlets, because these elements are common to published continuous-flow, contactless, and image-based DEP sorting workflows[2][3][6][7][12].
Experimental Procedure
• Prepare the cell suspension in the DEP-compatible medium used for the selected device and cell type, then introduce the sample into the sample inlet and buffer or sheath medium into the buffer inlet when the device design uses hydrodynamic focusing or sheath flow[2][3][9].
• Before sorting unknown samples, measure or screen DEP response across applied frequencies because several studies selected operating conditions by identifying frequencies at which target and non-target cells show different trajectories, crossover behavior, trapping, or lateral deflection[2][4][11][13][14].
• Prime the microfluidic chip with buffer before cell loading and remove air from the flow path, because protocol-level DEP chip operation emphasizes correct chip installation, buffer filling, sample filling, flow-rate adjustment, and avoidance of contamination as determinants of successful viable-cell recovery[3].
• Load the sample into the sample inlet and the DEP medium or sheath buffer into the buffer inlet, then establish stable flow before applying the electric field; published continuous-flow DEP sorting used sample and buffer streams and collected cells from separate outlets after DEP-induced trajectory differences[2][3][9].
• Apply an AC electric field at the frequency and voltage established for the device and cell type; reported examples include 3 MHz with 7.2-15.4 V peak-to-peak for hMSC/osteoblast separation, 0-300 kHz frequency testing for Jurkat separation in an integrated chip, and voltage-frequency optimization for live/dead leukemia-cell cDEP separation[2][3][6].
• For continuous-flow deflection sorting, run cells through the active DEP region and collect fractions from the designated outlets; in hMSC/osteoblast sorting, osteoblasts with stronger DEP deflection moved toward a lower outlet while hMSCs largely followed the original trajectory, and in platelet/blood-cell DEP-FFF, hydrodynamic focusing plus DEP separated platelets from other blood cells by trajectory differences[2][9].
• For contactless DEP enrichment, operate the device so electrodes are physically isolated from the sample channel by insulating barriers or membranes, because cDEP studies used this configuration to reduce direct electrode-sample contact while trapping or enriching target cells[6][7][8].
• For image-based DEP sorting, identify target cells by microscopy, select the cell or population of interest, and recover the selected cells after DEP manipulation; DEPArray studies describe single-cell or pure-population isolation for downstream molecular analysis[12].
• Quantify sorting performance by counting target and non-target cells in each outlet or recovered fraction and report collection efficiency, purity, recovery, and viability where measured; published DEP sorting studies used on-chip/off-chip counts, molecular confirmation, image-based identification, or live/dead assessment to evaluate performance[2][6][9][10][12].
• Use an untreated mixed sample or no-field condition as a negative control for passive flow behavior, and use a known separable cell mixture or bead/cell mixture as a positive process control when supported by the selected platform; studies compared trajectories with and without DEP activation and validated separation using known mixed populations[2][9][11].
• Before sorting unknown samples, measure or screen DEP response across applied frequencies because several studies selected operating conditions by identifying frequencies at which target and non-target cells show different trajectories, crossover behavior, trapping, or lateral deflection[2][4][11][13][14].
• Prime the microfluidic chip with buffer before cell loading and remove air from the flow path, because protocol-level DEP chip operation emphasizes correct chip installation, buffer filling, sample filling, flow-rate adjustment, and avoidance of contamination as determinants of successful viable-cell recovery[3].
• Load the sample into the sample inlet and the DEP medium or sheath buffer into the buffer inlet, then establish stable flow before applying the electric field; published continuous-flow DEP sorting used sample and buffer streams and collected cells from separate outlets after DEP-induced trajectory differences[2][3][9].
• Apply an AC electric field at the frequency and voltage established for the device and cell type; reported examples include 3 MHz with 7.2-15.4 V peak-to-peak for hMSC/osteoblast separation, 0-300 kHz frequency testing for Jurkat separation in an integrated chip, and voltage-frequency optimization for live/dead leukemia-cell cDEP separation[2][3][6].
• For continuous-flow deflection sorting, run cells through the active DEP region and collect fractions from the designated outlets; in hMSC/osteoblast sorting, osteoblasts with stronger DEP deflection moved toward a lower outlet while hMSCs largely followed the original trajectory, and in platelet/blood-cell DEP-FFF, hydrodynamic focusing plus DEP separated platelets from other blood cells by trajectory differences[2][9].
• For contactless DEP enrichment, operate the device so electrodes are physically isolated from the sample channel by insulating barriers or membranes, because cDEP studies used this configuration to reduce direct electrode-sample contact while trapping or enriching target cells[6][7][8].
• For image-based DEP sorting, identify target cells by microscopy, select the cell or population of interest, and recover the selected cells after DEP manipulation; DEPArray studies describe single-cell or pure-population isolation for downstream molecular analysis[12].
• Quantify sorting performance by counting target and non-target cells in each outlet or recovered fraction and report collection efficiency, purity, recovery, and viability where measured; published DEP sorting studies used on-chip/off-chip counts, molecular confirmation, image-based identification, or live/dead assessment to evaluate performance[2][6][9][10][12].
• Use an untreated mixed sample or no-field condition as a negative control for passive flow behavior, and use a known separable cell mixture or bead/cell mixture as a positive process control when supported by the selected platform; studies compared trajectories with and without DEP activation and validated separation using known mixed populations[2][9][11].
Troubleshooting
Cells do not separate into distinct outlets or recovered fractions.
Possible cause:The chosen frequency or voltage does not create sufficiently different DEP responses between the target and background cells.
Literature-supported solution:
Perform a frequency-response screen and choose conditions that maximize differential trajectory, crossover, trapping, or deflection behavior for the specific cell pair[2][4][11][13][14].
Cells trap at electrode edges and recovery decreases.
Possible cause:Strong positive DEP can slow or trap cells at electrode edges.
Literature-supported solution:
Use alternating on/off AC-field control when supported by the device design, as this was used in continuous-flow hMSC/osteoblast sorting to allow cells to traverse electrodes while maintaining lateral deflection[2].
Reduced viability after DEP enrichment.
Possible cause:Device geometry and electric-field exposure can affect viability.
Literature-supported solution:
Use contactless DEP geometries or cell-scale microstructures when appropriate, because cDEP and microstructured cDEP platforms were reported to improve recovery or viability relative to direct electrode exposure or earlier geometries[6][8].
Chip operation gives inconsistent collection.
Possible cause:Incorrect chip filling, unstable flow, cell concentration mismatch, or contamination.
Literature-supported solution:
Follow protocol-level chip installation, buffer filling, sample filling, flow-rate adjustment, and contamination-control steps before running the DEP separation[3].
References:
- [1]. Wang XB, et al. Cell separation by dielectrophoretic field-flow-fractionation. Anal Chem. 2000;72(4):832-839. [Content Brief]
- [2]. Song H, Rosano JM, Wang Y, Garson CJ, Prabhakarpandian B, Pant K, Lai E, et al. Continuous-flow sorting of stem cells and differentiation products based on dielectrophoresis. Lab Chip. 2015;15(5):1320-1328. [Content Brief]
- [3]. Koba K, et al. Protocol of living cell separation using the microfluidic dielectrophoresis integrated chip. STAR Protoc. 2022;3(3):101527. [Content Brief]
- [4]. Oshiro K, et al. Fabrication of a new all-in-one microfluidic dielectrophoresis integrated chip and living cell separation. iScience. 2022;25(2):103776. [Content Brief]
- [5]. Hu X, et al. Marker-specific sorting of rare cells using dielectrophoresis. Proc Natl Acad Sci U S A. 2005;102(44):15757-15761. [Content Brief]
- [6]. Shafiee H, et al. Selective isolation of live/dead cells using contactless dielectrophoresis (cDEP). Lab Chip. 2010;10(4):438-445. [Content Brief]
- [7]. Elvington ES, et al. Label-free isolation and enrichment of cells through contactless dielectrophoresis. J Vis Exp. 2013;(79):50634. [Content Brief]
- [8]. Čemažar J, et al. Enhanced contactless dielectrophoresis enrichment and isolation platform via cell-scale microstructures. Biomicrofluidics. 2016;10(1):014109. [Content Brief]
- [9]. Piacentini N, et al. Separation of platelets from other blood cells in continuous-flow by dielectrophoresis field-flow-fractionation. Biomicrofluidics. 2011;5(3):34122-341228. [Content Brief]
- [10]. Shim S, et al. Antibody-independent isolation of circulating tumor cells by continuous-flow dielectrophoresis. Biomicrofluidics. 2013;7(1):011807. [Content Brief]
- [11]. Alshareef M, et al. Separation of tumor cells with dielectrophoresis-based microfluidic chip. Biomicrofluidics. 2013;7(1):011803. [Content Brief]
- [12]. Di Trapani M, et al. DEPArray™ system: an automatic image-based sorter for isolation of pure circulating tumor cells. Cytometry A. 2018;93(12):1260-1266. [Content Brief]
- [13]. Prieto JL, et al. Frequency discretization in dielectrophoretic assisted cell sorting arrays to isolate neural cells. Lab Chip. 2012;12(12):2182-2189. [Content Brief]
- [14]. Flanagan LA, et al. Unique dielectric properties distinguish stem cells and their differentiated progeny. Stem Cells. 2008;26(3):656-665. [Content Brief]
LinkedIn
Researchgate
Instagram
X
Facebook
WhatsApp
Reddit
Mail