High throughput particle analysis: combining dielectrophoretic particle focussing with confocal optical detection.

A micro flow cytometer has been fabricated that detects and counts fluorescent particles flowing through a microchannel at high speed based upon their fluorescence emission intensity. Dielectrophoresis is used to continuously focus particles within the flowing fluid stream into the centre of the device, which is 40 microm high and 250 microm wide. The method ensures that all the particles pass through an interrogation region approximately 5 microm in diameter, which is created by focusing a beam of light into a spot. The functioning of the device was demonstrated by detecting and counting fluorescent latex particles at a rate of up to 250 particles/s. A mixture of three different populations of latex particle was used, each sub-population with a distinct level of fluorescent intensity. The device was evaluated by comparison with a conventional fluorescent activated cell sorter (FACS) and numerical simulation demonstrated that for 6 microm beads, and for this design of chip the theoretical throughput is of the order of 1000 particles/s (corresponding to a particle velocity of 10 mm s(-1)).

[1]  A Scherer,et al.  A microfabricated device for sizing and sorting DNA molecules. , 1999, Proceedings of the National Academy of Sciences of the United States of America.

[2]  S. Gawad,et al.  Micromachined impedance spectroscopy flow cytometer for cell analysis and particle sizing. , 2001, Lab on a chip.

[3]  J. Michael Ramsey,et al.  Microchip flow cytometry using electrokinetic focusing. , 1999, Analytical chemistry.

[4]  S. Quake,et al.  An Integrated Microfabricated Cell Sorter , 2022 .

[5]  H. Morgan,et al.  Microdevices for dielectrophoretic flow - through cell separation , 2003, IEEE Engineering in Medicine and Biology Magazine.

[6]  Mehmet Toner,et al.  A microfabrication-based dynamic array cytometer. , 2002, Analytical chemistry.

[7]  K. Mogensen,et al.  Measurements of scattered light on a microchip flow cytometer with integrated polymer based optical elements. , 2004, Lab on a chip.

[8]  J. Michael Ramsey,et al.  Electrokinetic Focusing in Microfabricated Channel Structures , 1997 .

[9]  N. Sundararajan,et al.  Three-dimensional hydrodynamic focusing in polydimethylsiloxane (PDMS) microchannels , 2004, Journal of Microelectromechanical Systems.

[10]  J. Kutter,et al.  Integrating advanced functionality in a microfabricated high-throughput fluorescent-activated cell sorter. , 2003, Lab on a chip.

[11]  G. van den Engh,et al.  High-speed cell sorting: fundamentals and recent advances. , 2003, Current opinion in biotechnology.

[12]  W. Göhde,et al.  Affordable CD4+ T‐cell counts on ‘single‐platform’ flow cytometers I. Primary CD4 gating , 2000, British journal of haematology.

[13]  Alan P. Morrison,et al.  Development of a microfluidic device for fluorescence activated cell sorting , 2002 .

[14]  M. McClain,et al.  Flow cytometry of Escherichia coli on microfluidic devices. , 2001, Analytical chemistry.

[15]  G. Gradl,et al.  A 3-D microelectrode system for handling and caging single cells and particles , 1999 .

[16]  Hywel Morgan,et al.  Numerical solution of the dielectrophoretic and travelling wave forces for interdigitated electrode arrays using the finite element method , 2002 .

[17]  Gwo-Bin Lee,et al.  Hydrodynamic Focusing for a Micromachined Flow Cytometer , 2001 .

[18]  D. Holmes,et al.  AC electrokinetic focussing in microchannels: micro- and nanoparticles , 2003 .

[19]  P. Cherukat,et al.  The inertial lift on a rigid sphere in a linear shear flow field near a flat wall , 1994, Journal of Fluid Mechanics.

[20]  Thomas B. Jones,et al.  Electromechanics of Particles , 1995 .

[21]  H Morgan,et al.  3D focusing of nanoparticles in microfluidic channels. , 2003, IEE proceedings. Nanobiotechnology.

[22]  Torsten Müller,et al.  The influence of higher moments on particle behaviour in dielectrophoretic field cages , 1999 .

[23]  M. Stelzle,et al.  Microdevices for manipulation and accumulation of micro‐ and nanoparticles by dielectrophoresis , 2003, Electrophoresis.

[24]  Urban Seger,et al.  Cell immersion and cell dipping in microfluidic devices. , 2004, Lab on a chip.

[25]  S G Shirley,et al.  Dielectrophoretic sorting of particles and cells in a microsystem. , 1998, Analytical chemistry.

[26]  G. Fuhr,et al.  Trapping in AC octode field cages , 2000 .

[27]  F. White.  Viscous Fluid Flow , 1974 .

[28]  George Janossy,et al.  Affordable CD4(+) T-cell counts on 'single-platform' flow cytometers I. Primary CD4 gating. , 2000 .

[29]  Hywel Morgan,et al.  AC ELECTROKINETICS: COLLOIDS AND NANOPARTICLES. , 2002 .

[30]  A. Acrivos,et al.  The lift on a small sphere touching a plane in the presence of a simple shear flow , 1985 .

[31]  S. Quake,et al.  A microfabricated fluorescence-activated cell sorter , 1999, Nature Biotechnology.

[32]  Ryuji Koyama,et al.  Counting and sizing of particles and particle agglomerates in a microfluidic device using laser light scattering: application to a particle-enhanced immunoassay. , 2003, Lab on a chip.