High-throughput continuous dielectrophoretic separation of neural stem cells

Abstract

We created an integrated microfluidic cell separation system that incorporates hydrophoresis and dielectrophoresis modules to facilitate high-throughput continuous cell separation. The hydrophoresis module consists of a serpentine channel with ridges and trenches to generate a diverging fluid flow that focuses cells into two streams along the channel edges. The dielectrophoresis module is composed of a chevron-shaped electrode array. Separation in the dielectrophoresis module is driven by inherent cell electrophysiological properties and does not require cell-type-specific labels. The chevron shape of the electrode array couples with fluid flow in the channel to enable continuous sorting of cells to increase throughput. We tested the new system with mouse neural stem cells since their electrophysiological properties reflect their differentiation capacity (e.g., whether they will differentiate into astrocytes or neurons). The goal of our experiments was to enrich astrocyte-biased cells. Sorting parameters were optimized for each batch of neural stem cells to ensure effective and consistent separations. The continuous sorting design of the device significantly improved sorting throughput and reproducibility. Sorting yielded two cell fractions, and we found that astrocyte-biased cells were enriched in one fraction and depleted from the other. This is an advantage of the new continuous sorting device over traditional dielectrophoresis-based sorting platforms that target a subset of cells for enrichment but do not provide a corresponding depleted population. The new microfluidic dielectrophoresis cell separation system improves label-free cell sorting by increasing throughput and delivering enriched and depleted cell subpopulations in a single sort.

Insulator Based Dielectrophoresis: Micro, Nano, and Molecular Scale Biological Applications

“…Electrode-based DEP has been routinely used to manipulate particles [ 14 , 32 , 59 , 60 ] and cells [ 9 , 57 , 61 ]. Electrodes in eDEP are generally made of electrically conductive materials, such as silver, brass, and gold.…”

“…Due to the application of DEP on neutral particles, it became apparent that the same electric fields can be employed to manipulate biological cells. The findings by Pohl paved the way for current research on inhomogeneous electric fields in biology [ 1 , 6 , 7 , 8 , 9 ].…”

Electrical Impedance Spectroscopy for Monitoring Chemoresistance of Cancer Cells

“…The cell patterning capabilities of EIS combined with DEP can be employed to build complex 3D microenvironments that represent in vivo cancer conditions. Another aspect of DEP is its implementation to continuously sort a variety of cells [ 81 , 101 , 102 , 103 , 104 ], thus an exciting possibility is to sort CSCs from non-CSCs prior to impedance monitoring. These techniques can also be used for drug optimization and monitoring as well as to understand the molecular and environmental driving forces involved in plasticity.…”

Continuous ES/Feeder Cell-Sorting Device Using Dielectrophoresis and Controlled Fluid Flow

“…Our newly developed DEP cell-sorting system does not require antibodies, fluorescence dyes, magnetic beads, or expensive equipment. In addition, the process of our DEP cell-sorting system was simple when compared to other DEP cell-sorting systems [41][42][43][44][45][46], with no complicated processes and with a high extensibility. Furthermore, our DEP cell-sorting system does not require a numerical analysis of the fluid-flow in the DEP chamber.…”