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Dielectrophoresis microsystem with integrated flow cytometers for on‐line monitoring of sorting efficiency
Author(s) -
Wang Zhenyu,
Hansen Ole,
Petersen Peter K.,
Rogeberg Anders,
Kutter Jörg P.,
Bang Dang D.,
Wolff Anders
Publication year - 2006
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.200600422
Subject(s) - dielectrophoresis , microfluidics , sorting , filter (signal processing) , microsystem , materials science , cell sorting , biological system , volumetric flow rate , nanotechnology , optoelectronics , computer science , flow cytometry , physics , biology , quantum mechanics , computer vision , genetics , programming language
Dielectrophoresis (DEP) and flow cytometry are powerful technologies and widely applied in microfluidic systems for handling and measuring cells and particles. Here, we present a novel microchip with a DEP selective filter integrated with two microchip flow cytometers (FCs) for on‐line monitoring of cell sorting processes. On the microchip, the DEP filter is integrated in a microfluidic channel network to sort yeast cells by positive DEP. The two FCs detection windows are set upstream and downstream of the DEP filter. When a cell passes through the detection windows, the light scattered by the cell is measured by integrated polymer optical elements (waveguide, lens, and fiber coupler). By comparing the cell counting rates measured by the two FCs, the collection efficiency of the DEP filter can be determined. The chips were used for quantitative determination of the effect of flow rate, applied voltage, conductivity of the sample, and frequency of the electric field on the sorting efficiency. A theoretical model for the capture efficiency was developed and a reasonable agreement with the experimental results observed. Viable and non‐viable yeast cells showed different frequency dependencies and were sorted with high efficiency. At 2 MHz, more than 90% of the viable and less than 10% of the non‐viable cells were captured on the DEP filter. The presented approach provides quantitative real‐time data for sorting a large number of cells and will allow optimization of the conditions for, e.g. , collecting cancer cells on a DEP filter while normal cells pass through the system. Furthermore, the microstructure is simple to fabricate and can easily be integrated with other microstructures for lab‐on‐a‐chip applications.