201
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Wu MH, Huang SB, Lee GB. Microfluidic cell culture systems for drug research. LAB ON A CHIP 2010; 10:939-56. [PMID: 20358102 DOI: 10.1039/b921695b] [Citation(s) in RCA: 268] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
In pharmaceutical research, an adequate cell-based assay scheme to efficiently screen and to validate potential drug candidates in the initial stage of drug discovery is crucial. In order to better predict the clinical response to drug compounds, a cell culture model that is faithful to in vivo behavior is required. With the recent advances in microfluidic technology, the utilization of a microfluidic-based cell culture has several advantages, making it a promising alternative to the conventional cell culture methods. This review starts with a comprehensive discussion on the general process for drug discovery and development, the role of cell culture in drug research, and the characteristics of the cell culture formats commonly used in current microfluidic-based, cell-culture practices. Due to the significant differences in several physical phenomena between microscale and macroscale devices, microfluidic technology provides unique functionality, which is not previously possible by using traditional techniques. In a subsequent section, the niches for using microfluidic-based cell culture systems for drug research are discussed. Moreover, some critical issues such as cell immobilization, medium pumping or gradient generation in microfluidic-based, cell-culture systems are also reviewed. Finally, some practical applications of microfluidic-based, cell-culture systems in drug research particularly those pertaining to drug toxicity testing and those with a high-throughput capability are highlighted.
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Affiliation(s)
- Min-Hsien Wu
- Graduate Institute of Biochemical and Biomedical Engineering, Chang Gung University, Taoyuan, Taiwan
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202
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Zhu J, Tzeng TRJ, Xuan X. Continuous dielectrophoretic separation of particles in a spiral microchannel. Electrophoresis 2010; 31:1382-8. [DOI: 10.1002/elps.200900736] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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203
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Single-cell analysis and isolation for microbiology and biotechnology: methods and applications. Appl Microbiol Biotechnol 2010; 86:1281-92. [DOI: 10.1007/s00253-010-2524-4] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2010] [Revised: 02/23/2010] [Accepted: 02/24/2010] [Indexed: 01/14/2023]
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204
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Ito H, Kato R, Ino K, Honda H. Magnetic manipulation device for the optimization of cell processing conditions. J Biosci Bioeng 2010; 109:182-8. [DOI: 10.1016/j.jbiosc.2009.07.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2009] [Revised: 07/14/2009] [Accepted: 07/15/2009] [Indexed: 01/09/2023]
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205
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Chen CH, Cho SH, Tsai F, Erten A, Lo YH. Microfluidic cell sorter with integrated piezoelectric actuator. Biomed Microdevices 2010; 11:1223-31. [PMID: 19649710 PMCID: PMC2776170 DOI: 10.1007/s10544-009-9341-5] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
We demonstrate a low-power (<0.1 mW), low-voltage (<10 V(p-p)) on-chip piezoelectrically actuated micro-sorter that can deflect single particles and cells at high-speed. With rhodamine in the stream, switching of flow between channels can be visualized at high actuation frequency (micro1.7 kHz). The magnitude of the cell deflection can be precisely controlled by the magnitude and waveform of input voltage. Both simulation and experimental results indicate that the drag force imposed on the suspended particle/cell by the instantaneous fluid displacement can alter the trajectory of the particle/cell of any size, shape, and density of interest in a controlled manner. The open-loop E. Coli cell deflection experiment demonstrates that the sorting mechanism can produce a throughput of at least 330 cells/s, with a promise of a significantly higher throughput for an optimized design. To achieve close-loop sorting operation, fluorescence detection, real-time signal processing, and field-programmable-gate-array (FPGA) implementation of the control algorithms were developed to perform automated sorting of fluorescent beads. The preliminary results show error-free sorting at a sorting efficiency of micro 70%. Since the piezoelectric actuator has an intrinsic response time of 0.1-1 ms and the sorting can be performed under high flowrate (particle speed of micro 1-10 cm/s), the system can achieve a throughput of >1,000 particles/s with high purity.
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Affiliation(s)
- Chun H Chen
- Department of Bioengineering, University of California at San Diego, La Jolla, CA 92093, USA.
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206
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Ranjan N, Mertig M, Cuniberti G, Pompe W. Dielectrophoretic growth of metallic nanowires and microwires: theory and experiments. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:552-559. [PMID: 19924880 DOI: 10.1021/la902026e] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Dielectrophoresis-assisted growth of metallic nanowires from an aqueous salt solution has been previously reported, but so far there has been no clear understanding of the process leading to such a bottom-up assembly. The present work, based on a series of experiments to grow metallic nano- and microwires by dielectrophoresis, provides a general theoretical description of the growth of such wires from an aqueous salt solution. Palladium nanowires and silver microwires have been grown between gold electrodes from their aqueous salt solution via dielectrophoresis. Silver microwire growth has been observed in situ using light microscopy. From these experiments, a basic model of dielectrophoresis-driven wire growth is developed. This model explains the dependence of the growth on the frequency and the local field enhancement at the electrode asperities. Such a process proves instrumental in the growth of metallic nanowires with controlled morphology and site specificity between the electrodes.
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Affiliation(s)
- Nitesh Ranjan
- Institute for Materials Science and Max Bergmann Center of Biomaterials, Dresden University of Technology, 01062 Dresden, Germany.
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207
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Kirschbaum M, Jaeger MS, Duschl C. Correlating short-term Ca(2+) responses with long-term protein expression after activation of single T cells. LAB ON A CHIP 2009; 9:3517-3525. [PMID: 20024031 DOI: 10.1039/b911865a] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
In order to elucidate the dynamics of cellular processes that are induced in context with intercellular communication, defined events along the signal transduction cascade and subsequent activation steps have to be analyzed on the level of individual cells and correlated with each other. Here we present an approach that allows the initiation of cell-cell or cell-particle interactions and the analysis of cellular reactions within various regimes while the identity of each individual cell is preserved. It utilizes dielectrophoresis (DEP) and microfluidics in a lab-on-chip system. With high spatial and temporal precision we contacted single T cells with functionalized microbeads and monitored their immediate cytosolic Ca(2+) response. After this, the cells were released from the chip system and cultivated further. Expression of the activation marker molecule CD69 was analyzed the next day and correlated with the previously recorded Ca(2+) signal for each individual cell. We found a significant difference in the patterns of Ca(2+) traces between activated and non-activated cells, which shows that Ca(2+) signals in T cells can provide early information about a later reaction of the cell. Although T cells are non-excitable cells, we also observed irregular Ca(2+) transients upon exposure to the DEP field only. These Ca(2+) signals depended on exposure time, electric field strength and field frequency. By minimizing their occurrence rate, we could identify experimental conditions that caused the least interference with the physiology of the cell.
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Affiliation(s)
- Michael Kirschbaum
- Fraunhofer Institute for Biomedical Engineering (IBMT), Am Muehlenberg 13, 14476 Potsdam, Germany
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208
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Adams JD, Tom Soh H. Perspectives on utilizing unique features of microfluidics technology for particle and cell sorting. ACTA ACUST UNITED AC 2009; 14:331-340. [PMID: 20161387 DOI: 10.1016/j.jala.2009.06.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Sample preparation is often the most tedious and demanding step in an assay, but it also plays an essential role in determining the quality of results. As biological questions and analytical methods become increasingly sophisticated, there is a rapidly growing need for systems that can reliably and reproducibly separate cells and particles with high purity, throughput and recovery. Microfluidics technology represents a compelling approach in this regard, allowing precise control of separation forces for high performance separation in inexpensive, or even disposable, devices. In addition, microfluidics technology enables the fabrication of arrayed and integrated systems that operate either in parallel or in tandem, in a capacity that would be difficult to achieve in macro-scale systems. In this report, we use recent examples from our work to illustrate the potential of microfluidic cell- and particle-sorting devices. We demonstrate the potential of chip-based high-gradient magnetophoresis that enable high-purity separation through reversible trapping of target particles paired with high-stringency washing with minimal loss. We also describe our work in the development of devices that perform simultaneous multi-target sorting, either through precise control of magnetic and fluidic forces or through the integration of multiple actuation forces into a single monolithic device. We believe that such devices may serve as a powerful "front-end" module of highly integrated analytical platforms capable of providing actionable diagnostic information directly from crude, unprocessed samples - the success of such systems may hold the key to advancing point-of-care diagnostics and personalized medicine.
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Affiliation(s)
- Jonathan D Adams
- Department of Physics, University of California, Santa Barbara, CA, 93106, USA
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209
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Peyman SA, Kwan EY, Margarson O, Iles A, Pamme N. Diamagnetic repulsion—A versatile tool for label-free particle handling in microfluidic devices. J Chromatogr A 2009; 1216:9055-62. [DOI: 10.1016/j.chroma.2009.06.039] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2009] [Revised: 06/04/2009] [Accepted: 06/12/2009] [Indexed: 11/24/2022]
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210
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Hall SS, Daugherty PS. Quantitative specificity-based display library screening identifies determinants of antibody-epitope binding specificity. Protein Sci 2009; 18:1926-34. [PMID: 19610073 DOI: 10.1002/pro.203] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Despite the critical importance of molecular specificity in bimolecular systems, in vitro display technologies have been applied extensively for affinity maturation of peptides and antibodies without explicitly measuring the specificity of the desired interaction. We devised a general strategy to measure, screen, and evolve specificity of protein ligand interactions analogous to widely used affinity maturation strategies. The specificity of binding to target and nontarget antibodies labeled with spectrally distinct fluorophores was measured simultaneously in protein mixtures via multiparameter flow cytometry, thereby enabling screening for high target antibody specificity. Isolated antibody specific ligands exhibited varying specificity, revealing critical amino acid determinants for target recognition and nontarget avoidance in complex mixtures. Molecular specificity in the mixture was further enhanced by quantitative directed evolution, yielding a family of epitopes exhibiting improved specificities equivalent, or superior to, the native peptide antigen to which the antibody was raised. Specificity screening simultaneously favored affinity, yielding ligands with three-fold improved affinity relative to the parent epitope. Quantitative specificity screening will be useful to screen, evolve, and characterize the specificity of protein and peptide interactions for molecular recognition applications.
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Affiliation(s)
- Sejal S Hall
- The Institute for Energy Efficiency, University of California, Santa Barbara, California 93106, USA
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211
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Cheng IF, Froude VE, Zhu Y, Chang HC, Chang HC. A continuous high-throughput bioparticle sorter based on 3D traveling-wave dielectrophoresis. LAB ON A CHIP 2009; 9:3193-201. [PMID: 19865725 DOI: 10.1039/b910587e] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
We present a high throughput (maximum flow rate approximately 10 microl/min or linear velocity approximately 3 mm/s) continuous bio-particle sorter based on 3D traveling-wave dielectrophoresis (twDEP) at an optimum AC frequency of 500 kHz. The high throughput sorting is achieved with a sustained twDEP particle force normal to the continuous through-flow, which is applied over the entire chip by a single 3D electrode array. The design allows continuous fractionation of micron-sized particles into different downstream sub-channels based on differences in their twDEP mobility on both sides of the cross-over. Conventional DEP is integrated upstream to focus the particles into a single levitated queue to allow twDEP sorting by mobility difference and to minimize sedimentation and field-induced lysis. The 3D electrode array design minimizes the offsetting effect of nDEP (negative DEP with particle force towards regions with weak fields) on twDEP such that both forces increase monotonically with voltage to further increase the throughput. Effective focusing and separation of red blood cells from debris-filled heterogeneous samples are demonstrated, as well as size-based separation of poly-dispersed liposome suspensions into two distinct bands at 2.3 to 4.6 microm and 1.5 to 2.7 microm, at the highest throughput recorded in hand-held chips of 6 microl/min.
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Affiliation(s)
- I-Fang Cheng
- Institute of Nanotechnology and Microsystem Engineering, National Cheng Kung University, Tainan, Taiwan, ROC
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212
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Le Gac S, van den Berg A. Single cells as experimentation units in lab-on-a-chip devices. Trends Biotechnol 2009; 28:55-62. [PMID: 19914725 DOI: 10.1016/j.tibtech.2009.10.005] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2009] [Revised: 10/12/2009] [Accepted: 10/22/2009] [Indexed: 12/12/2022]
Abstract
'Lab-on-a-chip' technology (LOC) has now reached a mature state and is employed commonly in research in the life sciences. LOC devices make novel experimentation possible while providing a sophisticated environment for cellular investigation. As a next step, we introduce here the concept of a 'lab-in-a-cell': the use of a single cell as a minimal and highly confined experimental unit, or experimentation in the simple, but still unequalled, platform provided by nature itself. LOC provides the appropriate format and set of tools for LIC experimentation, and we discuss here three types of LIC investigation: the elucidation of signaling pathways; the creation of novel production units; and the use of microfluidics for assisted reproduction techniques.
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Affiliation(s)
- Séverine Le Gac
- BIOS The Lab-on-a-Chip Group, MESA+ Institute for Nanotechnology, University of Twente, The Netherlands
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213
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Khoshmanesh K, Zhang C, Tovar-Lopez FJ, Nahavandi S, Baratchi S, Kalantar-zadeh K, Mitchell A. Dielectrophoretic manipulation and separation of microparticles using curved microelectrodes. Electrophoresis 2009; 30:3707-17. [DOI: 10.1002/elps.200900079] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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214
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Han KH, Han SI, Frazier AB. Lateral displacement as a function of particle size using a piecewise curved planar interdigitated electrode array. LAB ON A CHIP 2009; 9:2958-64. [PMID: 19789750 DOI: 10.1039/b909753h] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
We describe the lateral displacement of a particle passing over a planar interdigitated electrode array at an angle as a function of the particle size. The lateral displacement was also measured as a function of the angle between the electrode and the direction of flow. A simplified line charge model was used for numerically estimating the lateral displacement of fluorescent polystyrene (PS) beads with three different diameters. Using the lateral displacement as a function of particle size, we developed a lateral dielectrophoretic (DEP) microseparator, which enables continuous discrimination of particles by size. The microchannel was divided into three regions, each with an electrode array placed at a different angle with respect to the direction of flow. The experiment using an admixture of 3-, 5-, and 10-microm PS beads showed that the lateral DEP microseparator could continuously separate out 99.86% of the 3-microm beads, 98.82% of the 5-microm beads, and 99.69% of the 10-microm beads, simply by using a 200-kHz 12-Vp-p AC voltage to create the lateral DEP force. The lateral DEP microseparator is thus a practical device for simultaneously separating particles according to size from a heterogeneous admixture.
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Affiliation(s)
- Ki-Ho Han
- School of Nano Engineering, Inje University, Obang-dong, Gimhae, GyongNam, 621-749, Republic of Korea.
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215
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Microfluidic chip: Next-generation platform for systems biology. Anal Chim Acta 2009; 650:83-97. [DOI: 10.1016/j.aca.2009.04.051] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2008] [Revised: 04/16/2009] [Accepted: 04/27/2009] [Indexed: 12/30/2022]
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216
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Liu W, Dechev N, Foulds IG, Burke R, Parameswaran A, Park EJ. A novel permalloy based magnetic single cell micro array. LAB ON A CHIP 2009; 9:2381-90. [PMID: 19636470 DOI: 10.1039/b821044f] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Devices capable of automatically aligning cells onto geometrical arrays are of great interest to biomedical researchers. Such devices can facilitate the study of numerous cells while the cells remain physically separated from one another. In this way, cell arrays reduce cell-to-cell interactions while the cells are all subjected to common stimuli, which allows individual cell behaviour to be revealed. The use of arrays allows for the parallel analysis of single cells, facilitates data logging, and opens the door to the use of automated machine-based single cell analysis techniques. A novel permalloy based magnetic single cell micro array (MSCMA) is presented in this paper. The MSCMA creates an array of magnetic traps by generating magnetic flux density peaks at predefined locations. When using cells labelled with immunomagnetic labels, the cells will interact with the magnetic fields, and can be captured at the magnetic trap sites. Prototypes of the MSCMA have been successfully fabricated and tested using both fixed and live Jurkat cells (10 microm average diameter) that were labelled. The prototypes performed as predicted during experimental trials. The experimental results show that the MSCMA can randomly array up to 136 single cells per square mm. The results also show that the number of single cells captured is a function of the trap site density of the MSCMA design and the cell density in the fluid sample.
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Affiliation(s)
- William Liu
- Department of Mechanical Engineering, University of Victoria, PO Box 3055 STN CSC, Victoria, BC, CanadaV8W 3P6.
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217
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Kim U, Soh HT. Simultaneous sorting of multiple bacterial targets using integrated dielectrophoretic-magnetic activated cell sorter. LAB ON A CHIP 2009; 9:2313-8. [PMID: 19636461 DOI: 10.1039/b903950c] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The ability to rapidly and accurately sort multiple types of biological targets-such as molecules, viruses, bacteria or mammalian cells-from complex sample mixtures is an essential component for a wide range of diagnostic and therapeutic strategies. However, most current selection methods for cell separation are either limited with regard to throughput, as is the case for Fluorescence Assisted Cell Sorting (FACS), or else only allow binary separation of targets that have been labeled via a single parameter, such as Magnetic Activated Cell Sorting (MACS). We report here the integrated Dielectrophoretic-Magnetic Activated Cell Sorter (iDMACS), an integrated platform that combines two different force fields in a single microfluidic device for highly efficient multi-target separation. We describe the underlying physics and design of the iDMACS device and demonstrate approximately 900-fold enrichment of multiple bacterial target cell types with over 95% purity after a single round of separation.
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Affiliation(s)
- Unyoung Kim
- Department of Mechanical Engineering, University of California, Santa Barbara, USA
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218
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Abstract
The physical properties of DNA are quite important for molecular genetics as well as for its nanotechnological applications. Studying the interactions of alternating current (AC) electric fields with deoxyribonucleic acid (DNA) allows one to draw conclusions about these properties. These interactions are usually investigated in two different ways. In dielectric spectroscopy, a DNA solution is placed in a homogeneous AC field and electronic parameters are measured over several frequency decades in the Hz to GHz range. These electronic data are then interpreted on the basis of physico-chemical models as a result of certain phenomena on the molecular level. In dielectrophoretic studies, a DNA solution is exposed to an inhomogeneous AC field and the spatial response of few or single molecules is monitored by optical or scanning force microscopy. This response can involve translation, elongation and orientation of the molecular strings. In this review, a survey is given of the literature dealing with the dielectric and dielectrophoretic properties of DNA as well as with applications of DNA dielectrophoresis.
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Affiliation(s)
- R Hölzel
- Fraunhofer Institute for Biomedical Engineering, Department of Molecular Bioanalytics and Bioelectronics, Potsdam-Golm, Germany.
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219
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Wang L, Lu J, Marchenko SA, Monuki ES, Flanagan LA, Lee AP. Dual frequency dielectrophoresis with interdigitated sidewall electrodes for microfluidic flow-through separation of beads and cells. Electrophoresis 2009; 30:782-91. [PMID: 19197906 DOI: 10.1002/elps.200800637] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
This paper presents a novel design and separation strategy for lateral flow-through separation of cells/particles in microfluidics by dual frequency coupled dielectrophoresis (DEP) forces enabled by vertical interdigitated electrodes embedded in the channel sidewalls. Unlike field-flow-fractionation-DEP separations in microfluidics, which utilize planar electrodes on the microchannel floor to generate a DEP force to balance the gravitational force and separate objects at different height locations, lateral separation is enabled by sidewall interdigitated electrodes that are used to generate non-uniform electric fields and balanced DEP forces along the width of the microchannel. In the current design, two separate AC electric fields are applied to two sets of independent interdigitated electrode arrays fabricated in the sidewalls of the microchannel to generate differential DEP forces that act on the cells/particles flowing through. Individual particles (cells or beads) will experience DEP forces differently due to the difference in their dielectric properties. The balance of the differential DEP forces from the electrode arrays will position dissimilar particles at distinct equilibrium planes across the width of the channel. When coupled with fluid flow, this results in lateral separation along the width of the microchannel and the separated particles can thus be automatically directed into branched channel outlets leading to different reservoirs for downstream processing. In this paper, we present the design and analysis of lateral separation enabled by dual frequency coupled DEP, and cell/bead and cell/cell separations are demonstrated with this lateral separation strategy. With vertical interdigitated electrodes on the sidewall, the height of the microchannel can be increased without losing the electric field strength in contrast to other multiple frequency DEP devices with planar electrodes. As a result, populations of cells can be separated simultaneously instead of one by one to enable high-throughput sorting microfluidic devices.
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Affiliation(s)
- Lisen Wang
- Department of Biomedical Engineering, University of California, Irvine, CA 92697, USA
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220
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Lei U, Huang CW, Chen J, Yang CY, Lo YJ, Wo A, Chen CF, Fung TW. A travelling wave dielectrophoretic pump for blood delivery. LAB ON A CHIP 2009; 9:1349-1356. [PMID: 19417900 DOI: 10.1039/b822809d] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The travelling wave dielectrophoretic pump studied here is essentially a rectangular straight micro-channel with an electrode array on part of its wall, and operated under an ac voltage with phase shift at neighbouring electrodes. The travelling wave dielectrophoretic force drives the cells, which drag the plasma, and after some sophisticated interaction between conventional dielectrophoresis, travelling wave dielectrophoresis and fluid mechanics, the whole blood is delivered. The pump was fabricated using MEMS techniques and studied in details for different parameters. It is found that the pumping velocity is maximized at an intermediate frequency around 20-30 MHz (varies with phase shift), and at an intermediate channel height at about 40 microm. The quasi-static average cell velocity can reach 15 microm s(-1) for a pump with 1 mm length and 16 electrodes (total array length 465 microm) operated at 5 V and 20 MHz with 90 degrees phase shift.
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Affiliation(s)
- U Lei
- National Taiwan University, Institute of Applied Mechanics, Taipei, 106, Taiwan.
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221
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Park J, Kim HS, Han A. Micropatterning of poly(dimethylsiloxane) using a photoresist lift-off technique for selective electrical insulation of microelectrode arrays. JOURNAL OF MICROMECHANICS AND MICROENGINEERING : STRUCTURES, DEVICES, AND SYSTEMS 2009; 19:65016. [PMID: 19946385 DOI: 10.1088/0960-1317/19/12/125014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A poly(dimethylsiloxane) (PDMS) patterning method based on a photoresist lift-off technique to make an electrical insulation layer with selective openings is presented. The method enables creating PDMS patterns with small features and various thicknesses without any limitation in the designs and without the need for complicated processes or expensive equipments. Patterned PDMS layers were created by spin-coating liquid phase PDMS on top of a substrate having sacrificial photoresist patterns, followed by a photoresist lift-off process. The thickness of the patterned PDMS layers could be accurately controlled (6.5-24 µm) by adjusting processing parameters such as PDMS spin-coating speeds, PDMS dilution ratios, and sacrificial photoresist thicknesses. PDMS features as small as 15 µm were successfully patterned and the effects of each processing parameter on the final patterns were investigated. Electrical resistance tests between adjacent electrodes with and without the insulation layer showed that the patterned PDMS layer functions properly as an electrical insulation layer. Biocompatibility of the patterned PDMS layer was confirmed by culturing primary neuron cells on top of the layer for up to two weeks. An extensive neuronal network was successfully formed, showing that this PDMS patterning method can be applied to various biosensing microdevices. The utility of this fabrication method was further demonstrated by successfully creating a patterned electrical insulation layer on flexible substrates containing multi-electrode arrays.
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Affiliation(s)
- Jaewon Park
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, TX 77843-3128
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222
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Wu Z, Willing B, Bjerketorp J, Jansson JK, Hjort K. Soft inertial microfluidics for high throughput separation of bacteria from human blood cells. LAB ON A CHIP 2009; 9:1193-9. [PMID: 19370236 DOI: 10.1039/b817611f] [Citation(s) in RCA: 155] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
We developed a new approach to separate bacteria from human blood cells based on soft inertial force induced migration with flow defined curved and focused sample flow inside a microfluidic device. This approach relies on a combination of an asymmetrical sheath flow and proper channel geometry to generate a soft inertial force on the sample fluid in the curved and focused sample flow segment to deflect larger particles away while the smaller ones are kept on or near the original flow streamline. The curved and focused sample flow and inertial effect were visualized and verified using a fluorescent dye primed in the device. First the particle behaviour was studied in detail using 9.9 and 1.0 microm particles with a polymer-based prototype. The prototype device is compact with an active size of 3 mm(2). The soft inertial effect and deflection distance were proportional to the fluid Reynolds number (Re) and particle Reynolds number (Re(p)), respectively. We successfully demonstrated separation of bacteria (Escherichia coli) from human red blood cells at high cell concentrations (above 10(8)/mL), using a sample flow rate of up to 18 microL/min. This resulted in at least a 300-fold enrichment of bacteria at a wide range of flow rates with a controlled flow spreading. The separated cells were proven to be viable. Proteins from fractions before and after cell separation were analyzed by gel electrophoresis and staining to verify the removal of red blood cell proteins from the bacterial cell fraction. This novel microfluidic process is robust, reproducible, simple to perform, and has a high throughput compared to other cell sorting systems. Microfluidic systems based on these principles could easily be manufactured for clinical laboratory and biomedical applications.
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Affiliation(s)
- Zhigang Wu
- Microsystem Technology, Department of Engineering Science, Uppsala University, Box 534, The Angstrom Laboratory, 751 21, Uppsala, Sweden.
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223
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Sugino H, Ozaki K, Shirasaki Y, Arakawa T, Shoji S, Funatsu T. On-chip microfluidic sorting with fluorescence spectrum detection and multiway separation. LAB ON A CHIP 2009; 9:1254-60. [PMID: 19370245 DOI: 10.1039/b815765k] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The microfluidic platform is an important tool for diagnosis and biomedical studies because it enables us to handle precious cells and infectious materials safely. We have developed an on-chip microfluidic sorter with fluorescence spectrum detection and multiway separation. The fluorescence spectrum of specimens (495-685 nm) in the microchannels was obtained every 2 ms using a 1 x 16 arrayed photomultiplier tube. The specimen was identified by its spectrum and collected into the corresponding channel based on our previously reported thermoreversible gelation polymer technique (Y. Shirasaki, J. Tanaka, H. Makazu, K. Tashiro, S. Shoji, S. Tsukita and T. Funatsu, Anal. Chem., 2006, 78, 695-701). Four kinds of fluorescence microspheres and three kinds of Escherichia coli cells, expressing different fluorescent proteins, were successfully separated with accuracy and purity better than 90% at a throughput of about one particle per second.
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Affiliation(s)
- Hirokazu Sugino
- Laboratory of Bio-Analytical Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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224
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Dielectrophoresis assisted concentration of micro-particles and their rapid quantitation based on optical means. Biomed Microdevices 2009; 11:987-95. [DOI: 10.1007/s10544-009-9316-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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225
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Novak S, Maver U, Peternel Š, Venturini P, Bele M, Gaberšček M. Electrophoretic deposition as a tool for separation of protein inclusion bodies from host bacteria in suspension. Colloids Surf A Physicochem Eng Asp 2009. [DOI: 10.1016/j.colsurfa.2009.03.023] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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226
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Takahashi M, Yoshino T, Takeyama H, Matsunaga T. Direct magnetic separation of immune cells from whole blood using bacterial magnetic particles displaying protein G. Biotechnol Prog 2009; 25:219-26. [PMID: 19197981 DOI: 10.1002/btpr.101] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Direct separation of target cells from mixed population, such as peripheral blood, umbilical cord blood, and bone marrow, is an essential technique for various therapeutic or diagnosis applications. In this study, novel particles were fabricated, and direct magnetic separation of immune cells from whole blood using such particles was performed. The magnetotactic bacterium Magnetospirillum magneticum AMB-1 synthesizes intracellular bacterial magnetic particles (BacMPs), and protein G was expressed on the surface of the BacMPs by gene fusion techniques with anchor proteins isolated from BacMP membrane. The BacMPs displaying protein G (protein G-BacMPs) had high binding capabilities to a wide range of antibody types, and various versions of protein G-BacMPs binding with different anti-CD monoclonal antibodies were constructed. Consequently, direct magnetic separation of immune cells from whole blood using protein G-BacMPs binding with anti-CD monoclonal antibodies was demonstrated. B lymphocytes (CD19+ cells) or T lymphocytes (CD3+ cells), which represent less than 0.05% in whole blood cells, were successfully separated at a purity level of more than 96%. This level was superior to that from previous reports using other magnetic separation approaches. The results of this study demonstrate the utility of protein G-BacMP and this particle may become a powerful tool for various therapeutic or diagnosis applications.
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Affiliation(s)
- Masayuki Takahashi
- Dept. of Biotechnology, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan
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227
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Park JS, Song SH, Jung HI. Continuous focusing of microparticles using inertial lift force and vorticity via multi-orifice microfluidic channels. LAB ON A CHIP 2009; 9:939-48. [PMID: 19294305 DOI: 10.1039/b813952k] [Citation(s) in RCA: 130] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
We developed a new microfluidic method for focusing microparticles through the combined use of inertial lift forces and turbulent secondary flows generated in a topographically patterned microchannel. The mechanism of particle focusing is based on the hydrodynamic inertial forces exerted on particles migrating along a non-circular microchannel, i.e.tubular pinch effect and wall effect, which induce particle movement away from walls and along a specific lateral position in the microchannel. With the extraordinary geometry of multi-orifice microchannel, an ordered and focused particle distribution was achieved at central or side regions according to a particle Reynolds number (Re(p)) range. The focusing of particles was controlled by the particle Reynolds number, microchannel length, and volume fraction of particles in suspension. This method will be beneficial in particle focusing processes in a microfluidic device since it offers continuous, high-throughput performance and simple operation.
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Affiliation(s)
- Jae-Sung Park
- School of Mechanical Engineering, Yonsei University, 262 Seongsan-no Seodaemun-gu, Seoul, 120-749, South Korea
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228
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Gascoyne PRC, Noshari J, Anderson TJ, Becker FF. Isolation of rare cells from cell mixtures by dielectrophoresis. Electrophoresis 2009; 30:1388-98. [PMID: 19306266 PMCID: PMC3754902 DOI: 10.1002/elps.200800373] [Citation(s) in RCA: 307] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The application of dielectrophoretic field-flow fractionation (depFFF) to the isolation of circulating tumor cells (CTCs) from clinical blood specimens was studied using simulated cell mixtures of three different cultured tumor cell types with peripheral blood. The depFFF method can not only exploit intrinsic tumor cell properties so that labeling is unnecessary but can also deliver unmodified, viable tumor cells for culture and/or all types of molecular analysis. We investigated tumor cell recovery efficiency as a function of cell loading for a 25 mm wide x 300 mm long depFFF chamber. More than 90% of tumor cells were recovered for small samples but a larger chamber will be required if similarly high recovery efficiencies are to be realized for 10 mL blood specimens used CTC analysis in clinics. We show that the factor limiting isolation efficiency is cell-cell dielectric interactions and that isolation protocols should be completed within approximately 15 min in order to avoid changes in cell dielectric properties associated with ion leakage.
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Affiliation(s)
- Peter R C Gascoyne
- Department of Molecular Pathology, University of Texas M. D. Anderson Cancer Center, Houston, TX 77030, USA.
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229
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Lou X, Qian J, Xiao Y, Viel L, Gerdon AE, Lagally ET, Atzberger P, Tarasow TM, Heeger AJ, Soh HT. Micromagnetic selection of aptamers in microfluidic channels. Proc Natl Acad Sci U S A 2009; 106:2989-94. [PMID: 19202068 PMCID: PMC2637280 DOI: 10.1073/pnas.0813135106] [Citation(s) in RCA: 247] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2008] [Indexed: 12/18/2022] Open
Abstract
Aptamers are nucleic acid molecules that have been selected in vitro to bind to their molecular targets with high affinity and specificity. Typically, the systematic evolution of ligands by exponential enrichment (SELEX) process is used for the isolation of specific, high-affinity aptamers. SELEX, however, is an iterative process requiring multiple rounds of selection and amplification that demand significant time and labor. Here, we describe an aptamer discovery system that is rapid, highly efficient, automatable, and applicable to a wide range of targets, based on the integration of magnetic bead-based SELEX process with microfluidics technology. Our microfluidic SELEX (M-SELEX) method exploits a number of unique phenomena that occur at the microscale and implements a design that enables it to manipulate small numbers of beads precisely and isolate high-affinity aptamers rapidly. As a model to demonstrate the efficiency of the M-SELEX process, we describe here the isolation of DNA aptamers that tightly bind to the light chain of recombinant Botulinum neurotoxin type A (with low-nanomolar dissociation constant) after a single round of selection.
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Affiliation(s)
- Xinhui Lou
- Departments of Materials
- Mechanical Engineering, and
| | | | - Yi Xiao
- Departments of Materials
- Mechanical Engineering, and
| | | | | | | | - Paul Atzberger
- Mathematics, University of California, Santa Barbara, CA 93106; and
| | - Theodore M. Tarasow
- Chemistry, Materials Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94551
| | | | - H. Tom Soh
- Departments of Materials
- Mechanical Engineering, and
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230
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Liu W, Dechev N, Lee SW, Foulds IG, Parameswaran A, Burke R, Park EJ. Development of a magnetic Single Cell Micro Array. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2009; 2008:3170-3. [PMID: 19163380 DOI: 10.1109/iembs.2008.4649877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Experiments using single cells are valuable for revealing individual cell behaviour, which is of interest to many biomedical researchers. In such experiments, various types of devices capable of aligning cells into organized arrays are often used. In this paper, we present a novel Single Cell Micro Array device that makes use of magnetic forces. Prototypes of this device have been fabricated, and successfully tested using Jurkat cells that have been labelled with nano-magnetic particles. Experimental results show that the prototypes are effective on capturing and placing the labelled cells in an array.
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Affiliation(s)
- W Liu
- Department of Mechanical Engineering, University of Victoria, BC, Canada.
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231
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Velev OD, Gangwal S, Petsev DN. Particle-localized AC and DC manipulation and electrokinetics. ACTA ACUST UNITED AC 2009. [DOI: 10.1039/b803015b] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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232
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Tsutsui H, Ho CM. Cell Separation by Non-Inertial Force Fields in Microfluidic Systems. MECHANICS RESEARCH COMMUNICATIONS 2009; 36:92-103. [PMID: 20046897 PMCID: PMC2776738 DOI: 10.1016/j.mechrescom.2008.08.006] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Cell and microparticle separation in microfluidic systems has recently gained significant attention in sample preparations for biological and chemical studies. Microfluidic separation is typically achieved by applying differential forces on the target particles to guide them into different paths. This paper reviews basic concepts and novel designs of such microfluidic separators with emphasis on the use of non-inertial force fields, including dielectrophoretic force, optical gradient force, magnetic force, and acoustic primary radiation force. Comparisons of separation performances with discussions on physiological effects and instrumentation issues toward point-of-care devices are provided as references for choosing appropriate separation methods for various applications.
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Affiliation(s)
- Hideaki Tsutsui
- Mechanical and Aerospace Engineering Department, University of California, Los Angeles, Los Angeles, CA 90095, United States
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233
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Choi S, Song S, Choi C, Park JK. Hydrophoretic Sorting of Micrometer and Submicrometer Particles Using Anisotropic Microfluidic Obstacles. Anal Chem 2008; 81:50-5. [DOI: 10.1021/ac801720x] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Sungyoung Choi
- Department of Bio and Brain Engineering, KAIST, 335 Gwahangno, Yuseong-gu, Daejeon 305-701, Republic of Korea
| | - Seungjeong Song
- Department of Bio and Brain Engineering, KAIST, 335 Gwahangno, Yuseong-gu, Daejeon 305-701, Republic of Korea
| | - Chulhee Choi
- Department of Bio and Brain Engineering, KAIST, 335 Gwahangno, Yuseong-gu, Daejeon 305-701, Republic of Korea
| | - Je-Kyun Park
- Department of Bio and Brain Engineering, KAIST, 335 Gwahangno, Yuseong-gu, Daejeon 305-701, Republic of Korea
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234
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Kim U, Qian J, Kenrick SA, Daugherty PS, Soh HT. Multitarget dielectrophoresis activated cell sorter. Anal Chem 2008; 80:8656-61. [PMID: 18939853 DOI: 10.1021/ac8015938] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The ability to rapidly and efficiently isolate specific viruses, bacteria, or mammalian cells from complex mixtures lies at the heart of biomedical applications ranging from in vitro diagnostics to cell transplantation therapies. Unfortunately, many current selection methods for cell separation, such as magnetic activated cell sorting (MACS), only allow the binary separation of target cells that have been labeled via a single parameter (e.g., magnetization). This limitation makes it challenging to simultaneously enrich multiple, distinct target cell types from a multicomponent sample. We describe here a novel approach to specifically label multiple cell types with unique synthetic dielectrophoretic tags that modulate the complex permittivities of the labeled cells, allowing them to be sorted with high purity using the multitarget dielectrophoresis activated cell sorter (MT-DACS) chip. Here we describe the underlying physics and design of the MT-DACS microfluidic device and demonstrate approximately 1000-fold enrichment of multiple bacterial target cell types in a single-pass separation.
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Affiliation(s)
- Unyoung Kim
- Department of Mechanical Engineering, University of California, Santa Barbara, California 93106, USA
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235
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Persson J, Augustsson P, Laurell T, Ohlin M. Acoustic microfluidic chip technology to facilitate automation of phage display selection. FEBS J 2008; 275:5657-66. [DOI: 10.1111/j.1742-4658.2008.06691.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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236
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Godin J, Chen CH, Cho SH, Qiao W, Tsai F, Lo YH. Microfluidics and photonics for Bio-System-on-a-Chip: a review of advancements in technology towards a microfluidic flow cytometry chip. JOURNAL OF BIOPHOTONICS 2008; 1:355-376. [PMID: 19343660 DOI: 10.1002/jbio.v1:5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Microfluidics and photonics come together to form a field commonly referred to as 'optofluidics'. Flow cytometry provides the field with a technology base from which both microfluidic and photonic components be developed and integrated into a useful device. This article reviews some of the more recent developments to familiarize a reader with the current state of the technologies and also highlights the requirements of the device and how researchers are working to meet these needs.
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Affiliation(s)
- Jessica Godin
- Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, CA, USA.
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237
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Godin J, Chen CH, Cho SH, Qiao W, Tsai F, Lo YH. Microfluidics and photonics for Bio-System-on-a-Chip: a review of advancements in technology towards a microfluidic flow cytometry chip. JOURNAL OF BIOPHOTONICS 2008; 1:355-76. [PMID: 19343660 PMCID: PMC2746115 DOI: 10.1002/jbio.200810018] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Microfluidics and photonics come together to form a field commonly referred to as 'optofluidics'. Flow cytometry provides the field with a technology base from which both microfluidic and photonic components be developed and integrated into a useful device. This article reviews some of the more recent developments to familiarize a reader with the current state of the technologies and also highlights the requirements of the device and how researchers are working to meet these needs.
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Affiliation(s)
- Jessica Godin
- Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, CA, USA.
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238
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Das SK, Chung S, Zervantonakis I, Atnafu J, Kamm RD. A microfluidic platform for studying the effects of small temperature gradients in an incubator environment. BIOMICROFLUIDICS 2008; 2:34106. [PMID: 19693373 PMCID: PMC2716926 DOI: 10.1063/1.2988313] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2008] [Accepted: 08/25/2008] [Indexed: 05/10/2023]
Abstract
Studies on the effects of variations in temperature and mild temperature gradients on cells, gels, and scaffolds are important from the viewpoint of biological function. Small differences in temperature are known to elicit significant variations in cell behavior and individual protein reactivity. For the study of thermal effects and gradients in vitro, it is important to develop microfluidic platforms which are capable of controlling temperature gradients in an environment which mimics the range of physiological conditions. In the present paper, such a microfluidic thermal gradient system (muTGS) system is proposed which can create and maintain a thermal gradient throughout a cell-seeded gel matrix using the hot and cold water supply integrated in the system in the form of a countercurrent heat exchanger. It is found that a uniform temperature gradient can be created and maintained in the device even inside a high temperature and high humidity environment of an incubator. With the help of a hot and cold circuit controlled from outside the incubator the temperature gradient can be regulated. A numerical simulation of the device demonstrates the thermal feature of the chip. Cell viability and activity under a thermal gradient are examined by placing human breast cancer cells in the device.
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239
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Gutstein HB, Morris JS, Annangudi SP, Sweedler JV. Microproteomics: analysis of protein diversity in small samples. MASS SPECTROMETRY REVIEWS 2008; 27:316-330. [PMID: 18271009 DOI: 10.1002/mas.v27:4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Proteomics, the large-scale study of protein expression in organisms, offers the potential to evaluate global changes in protein expression and their post-translational modifications that take place in response to normal or pathological stimuli. One challenge has been the requirement for substantial amounts of tissue in order to perform comprehensive proteomic characterization. In heterogeneous tissues, such as brain, this has limited the application of proteomic methodologies. Efforts to adapt standard methods of tissue sampling, protein extraction, arraying, and identification are reviewed, with an emphasis on those appropriate to smaller samples ranging in size from several microliters down to single cells. The effects of miniaturization on these analyses are highlighted using neuroscience-related examples, as are statistical issues unique to the high-dimensional datasets generated by proteomic experiments.
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Affiliation(s)
- Howard B Gutstein
- Department of Anesthesiology, University of Texas-MD Anderson Cancer Center, 1515 Holcombe Blvd., Box 110, Houston, TX 77030-4009, USA.
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240
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Gutstein HB, Morris JS, Annangudi SP, Sweedler JV. Microproteomics: analysis of protein diversity in small samples. MASS SPECTROMETRY REVIEWS 2008; 27:316-30. [PMID: 18271009 PMCID: PMC2743962 DOI: 10.1002/mas.20161] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Proteomics, the large-scale study of protein expression in organisms, offers the potential to evaluate global changes in protein expression and their post-translational modifications that take place in response to normal or pathological stimuli. One challenge has been the requirement for substantial amounts of tissue in order to perform comprehensive proteomic characterization. In heterogeneous tissues, such as brain, this has limited the application of proteomic methodologies. Efforts to adapt standard methods of tissue sampling, protein extraction, arraying, and identification are reviewed, with an emphasis on those appropriate to smaller samples ranging in size from several microliters down to single cells. The effects of miniaturization on these analyses are highlighted using neuroscience-related examples, as are statistical issues unique to the high-dimensional datasets generated by proteomic experiments.
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Affiliation(s)
- Howard B Gutstein
- Department of Anesthesiology, University of Texas-MD Anderson Cancer Center, 1515 Holcombe Blvd., Box 110, Houston, TX 77030-4009, USA.
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241
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Bhattacharya S, Salamat S, Morisette D, Banada P, Akin D, Liu YS, Bhunia AK, Ladisch M, Bashir R. PCR-based detection in a micro-fabricated platform. LAB ON A CHIP 2008; 8:1130-1136. [PMID: 18584089 DOI: 10.1039/b802227e] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We present a novel, on-chip system for the electrokinetic capture of bacterial cells and their identification using the polymerase chain reaction (PCR). The system comprises a glass-silicon platform with a set of micro-channels, -chambers, and -electrodes. A platinum thin film resistor, placed in the proximity of the chambers, is used for temperature monitoring. The whole chip assembly is mounted on a Printed Circuit Board (PCB) and wire-bonded to it. The PCB has an embedded heater that is utilized for PCR thermal cycle and is controlled by a Lab-View program. Similar to our previous work, one set of electrodes on the chip inside the bigger chamber (0.6 microl volume) is used for diverting bacterial cells from a flowing stream into to a smaller chamber (0.4 nl volume). A second set of interdigitated electrodes (in smaller chamber) is used to actively trap and concentrate the bacterial cells using dielectrophoresis (DEP). In the presence of the DEP force, with the cells still entrapped in the micro-chamber, PCR mix is injected into the chamber. Subsequently, PCR amplification with SYBR Green detection is used for genetic identification of Listeria monocytogenes V7 cells. The increase in fluorescence is recorded with a photomultiplier tube module mounted over an epifluorescence microscope. This integrated micro-system is capable of genetic amplification and identification of as few as 60 cells of L. monocytogenes V7 in less than 90 min, in 600 nl volume collected from a sample of 10(4) cfu ml(-1). Specificity trials using various concentrations of L. monocytogenes V7, Listeria innocua F4248, and Escherichia coli O157:H7 were carried out successfully using two different primer sets specific for a regulatory gene of L. monocytogenes, prfA and 16S rRNA primer specific for the Listeria spp., and no cross-reactivity was observed.
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242
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Perroud TD, Kaiser JN, Sy JC, Lane TW, Branda CS, Singh AK, Patel KD. Microfluidic-Based Cell Sorting of Francisella tularensis Infected Macrophages Using Optical Forces. Anal Chem 2008; 80:6365-72. [DOI: 10.1021/ac8007779] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Thomas D. Perroud
- Sandia National Laboratories, P.O. Box 969, Livermore, California 94551, and Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332
| | - Julia N. Kaiser
- Sandia National Laboratories, P.O. Box 969, Livermore, California 94551, and Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332
| | - Jay C. Sy
- Sandia National Laboratories, P.O. Box 969, Livermore, California 94551, and Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332
| | - Todd W. Lane
- Sandia National Laboratories, P.O. Box 969, Livermore, California 94551, and Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332
| | - Catherine S. Branda
- Sandia National Laboratories, P.O. Box 969, Livermore, California 94551, and Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332
| | - Anup K. Singh
- Sandia National Laboratories, P.O. Box 969, Livermore, California 94551, and Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332
| | - Kamlesh D. Patel
- Sandia National Laboratories, P.O. Box 969, Livermore, California 94551, and Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332
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243
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Dougherty GM, Rose KA, Tok JBH, Pannu SS, Chuang FYS, Sha MY, Chakarova G, Penn SG. The zeta potential of surface-functionalized metallic nanorod particles in aqueous solution. Electrophoresis 2008; 29:1131-9. [PMID: 18246574 DOI: 10.1002/elps.200700448] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Metallic nanoparticles suspended in aqueous solutions and functionalized with chemical and biological surface coatings are important elements in basic and applied nanoscience research. Many applications require an understanding of the electrokinetic or colloidal properties of such particles. We describe the results of experiments to measure the zeta potential of metallic nanorod particles in aqueous saline solutions, including the effects of pH, ionic strength, metallic composition, and surface functionalization state. Particle substrates tested include gold, silver, and palladium monometallic particles as well as gold/silver bimetallic particles. Surface functionalization conditions included 11-mercaptoundecanoic acid (MUA), mercaptoethanol (ME), and mercaptoethanesulfonic acid (MESA) self-assembled monolayers (SAMs), as well as MUA layers subsequently derivatized with proteins. For comparison, we present zeta potential data for typical charge-stabilized polystyrene particles. We compare experimental zeta potential data with theoretically predicted values for SAM-coated and bimetallic particles. The results of these studies are useful in predicting and controlling the aggregation, adhesion, and transport of functionalized metallic nanoparticles within microfluidic devices and other systems.
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244
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Evander M, Lenshof A, Laurell T, Nilsson J. Acoustophoresis in wet-etched glass chips. Anal Chem 2008; 80:5178-85. [PMID: 18489126 DOI: 10.1021/ac800572n] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Acoustophoresis in microfluidic structures has primarily been reported in silicon microfabricated devices. This paper demonstrates, for the first time, acoustophoresis performed in isotropically etched glass chips providing a performance that matches that of the corresponding silicon microdevices. The resonance mode characteristics of the glass chip were equal to those of the silicon chip at its fundamental resonance. At higher order resonance modes the glass chip displays resonances at lower frequencies than the silicon chip. The cross-sectional profiles of acoustically focused particle streams are also reported for the first time, displaying particles confined in a vertical band in the channel center for both glass and silicon chips. A particle extraction efficiency of 98% at flow rates up to 200 microL/min (2% particle concentration) is reported for the glass chip at the fundamental resonance. The glass and silicon chips displayed equal particle extraction performance when tested for increasing particle concentrations of 2-15%, at a flow velocity of 12.9 cm/s for the glass chip and 14.8 cm/s for the silicon chip.
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Affiliation(s)
- Mikael Evander
- The Department of Electrical Measurements, Lund University, P.O. Box 118, 211 00 Lund, Sweden.
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245
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Choi S, Song S, Choi C, Park JK. Sheathless focusing of microbeads and blood cells based on hydrophoresis. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2008; 4:634-41. [PMID: 18383190 DOI: 10.1002/smll.200700308] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
This paper presents a microfluidic device for sheathless focusing of microbeads and blood cells based on a hydrophoretic platform comprising a V-shaped obstacle array (VOA). The VOA generates lateral pressure gradients that induce helical recirculations. Following the focusing flow particles passing through the VOA are focused in the center of the channel. In the device, the focusing pattern can be modulated by varying the gap height of the VOA. To achieve complete focusing within 4.4% coefficient of variation, the relative size differences between the gap and the particle were 3 and 4 microm for 10 and 15 microm beads, respectively. Red blood cells were used to study the hydrophoretic focusing pattern of biconcave, disk-shaped particles.
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Affiliation(s)
- Sungyoung Choi
- Department of Bio and Brain Engineering Korea Advanced Institute of Science and Technology (KAIST) 335 Gwahangno, Yuseong-gu, Daejeon, Korea
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246
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Pommer MS, Zhang Y, Keerthi N, Chen D, Thomson JA, Meinhart CD, Soh HT. Dielectrophoretic separation of platelets from diluted whole blood in microfluidic channels. Electrophoresis 2008; 29:1213-8. [DOI: 10.1002/elps.200700607] [Citation(s) in RCA: 147] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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247
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Kersaudy-Kerhoas M, Dhariwal R, Desmulliez MPY. Recent advances in microparticle continuous separation. IET Nanobiotechnol 2008; 2:1-13. [PMID: 18298195 DOI: 10.1049/iet-nbt:20070025] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- M Kersaudy-Kerhoas
- Heriot-Watt University, MIcroSystems Engineering Centre, School of Engineering and Physical Sciences, Edinburgh, UK.
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248
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Pennathur S, Meinhart CD, Soh HT. How to exploit the features of microfluidics technology. LAB ON A CHIP 2008; 8:20-2. [PMID: 18094758 DOI: 10.1039/b717986n] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Affiliation(s)
- S Pennathur
- Department of Mechanical Engineering, University of California, Santa Barbara, USA. sumita@engineering. ucsb.edu
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249
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Selection of mammalian cells based on their cell-cycle phase using dielectrophoresis. Proc Natl Acad Sci U S A 2007; 104:20708-12. [PMID: 18093921 DOI: 10.1073/pnas.0708760104] [Citation(s) in RCA: 125] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
An effective, noninvasive means of selecting cells based on their phase within the cell cycle is an important capability for biological research. Current methods of producing synchronous cell populations, however, tend to disrupt the natural physiology of the cell or suffer from low synchronization yields. In this work, we report a microfluidic device that utilizes the dielectrophoresis phenomenon to synchronize cells by exploiting the relationship between the cell's volume and its phase in the cell cycle. The dielectrophoresis activated cell synchronizer (DACSync) device accepts an asynchronous mixture of cells at the inlet, fractionates the cell populations according to the cell-cycle phase (G(1)/S and G(2)/M), and elutes them through different outlets. The device is gentle and efficient; it utilizes electric fields that are 1-2 orders of magnitude below those used in electroporation and enriches asynchronous tumor cells in the G(1) phase to 96% in one round of sorting, in a continuous flow manner at a throughput of 2 x 10(5) cells per hour per microchannel. This work illustrates the feasibility of using laminar flow and electrokinetic forces for the efficient, noninvasive separation of living cells.
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250
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Boettcher M, Jaeger M, Kirschbaum M, Mueller T, Schnelle T, Duschl C. Gravitation-driven stress-reduced cell handling. Anal Bioanal Chem 2007; 390:857-63. [DOI: 10.1007/s00216-007-1751-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2007] [Revised: 10/25/2007] [Accepted: 11/12/2007] [Indexed: 10/22/2022]
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