Biomedical Microdevices

, Volume 9, Issue 4, pp 533–543

Automatic microfluidic platform for cell separation and nucleus collection

  • Chien-Hsuan Tai
  • Suz-Kai Hsiung
  • Chih-Yuan Chen
  • Mei-Lin Tsai
  • Gwo-Bin Lee
Article

DOI: 10.1007/s10544-007-9061-7

Cite this article as:
Tai, CH., Hsiung, SK., Chen, CY. et al. Biomed Microdevices (2007) 9: 533. doi:10.1007/s10544-007-9061-7

Abstract

This study reports a new biochip capable of cell separation and nucleus collection utilizing dielectrophoresis (DEP) forces in a microfluidic system comprising of micropumps and microvalves, operating in an automatic format. DEP forces operated at a low voltage (15 Vp–p) and at a specific frequency (16 MHz) can be used to separate cells in a continuous flow, which can be subsequently collected. In order to transport the cell samples continuously, a serpentine-shape (S-shape) pneumatic micropump device was constructed onto the chip device to drive the samples flow through the microchannel, which was activated by the pressurized air injection. The mixed cell samples were first injected into an inlet reservoir and driven through the DEP electrodes to separate specific samples. Finally, separated cell samples were collected individually in two outlet reservoirs controlled by microvalves. With the same operation principle, the nucleus of the specific cells can be collected after the cell lysis procedure. The pumping rate of the micropump was measured to be 39.8 μl/min at a pressure of 25 psi and a driving frequency of 28 Hz. For the cell separation process, the initial flow rate was 3 μl/min provided by the micropump. A throughput of 240 cells/min can be obtained by using the developed device. The DEP electrode array, microchannels, micropumps and microvalves are integrated on a microfluidic chip using micro-electro-mechanical-systems (MEMS) technology to perform several crucial procedures including cell transportation, separation and collection. The dimensions of the integrated chip device were measured to be 6 × 7 cm. By integrating an S-shape pump and pneumatic microvalves, different cells are automatically transported in the microchannel, separated by the DEP forces, and finally sorted to specific chambers. Experimental data show that viable and non-viable cells (human lung cancer cell, A549-luc-C8) can be successfully separated and collected using the developed microfluidic platform. The separation accuracy, depending on the DEP operating mode used, of the viable and non-viable cells are measured to be 84 and 81%, respectively. In addition, after cell lysis, the nucleus can be also collected using a similar scheme. The developed automatic microfluidic platform is useful for extracting nuclear proteins from living cells. The extracted nuclear proteins are ready for nuclear binding assays or the study of nuclear proteins.

Keywords

Dielectrophoresis forceMicropumpMicrovalveCell separationCell collectionMEMSMicrofluidics

Nomenclature

AC

Alternating current

Bio-MEMS

Bio-micro-electro-mechanical-systems

DEP

Dielectrophoresis

DMEM

Dulvecco’s modified eagle medium

DNA

Deoxyribonucleic acid

EMV

Electromagnetic valve

ER

Estrogen nuclear receptor

LIF

Laser induced fluorescence

LOC

Lab-on-a-chip

MEMS

Micro-electro-mechanical-systems

PDMS

Polydimethylsiloxane

PI

Propidium iodide

PR

Photoresist

SEM

Scanning electron microscope

S-shape

Serpentine-shape

Vp–p

Peak-to-peak Voltage

Copyright information

© Springer Science+Business Media, LLC 2007

Authors and Affiliations

  • Chien-Hsuan Tai
    • 1
  • Suz-Kai Hsiung
    • 1
  • Chih-Yuan Chen
    • 2
  • Mei-Lin Tsai
    • 2
  • Gwo-Bin Lee
    • 1
  1. 1.Department of Engineering ScienceNational Cheng Kung UniversityTainanTaiwan
  2. 2.Department of PhysiologyNational Cheng Kung UniversityTainanTaiwan