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Fabiano L, Pandey S, Brischwein M, Hasanzadeh Kafshgari M, Hayden O. Continuous Perfusion Experiments on 3D Cell Proliferation in Acoustic Levitation. MICROMACHINES 2024; 15:436. [PMID: 38675247 PMCID: PMC11051894 DOI: 10.3390/mi15040436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 03/18/2024] [Accepted: 03/21/2024] [Indexed: 04/28/2024]
Abstract
An acoustofluidic trap is used for accurate 3D cell proliferation and cell function analysis in levitation. The prototype trap can be integrated with any microscope setup, allowing continuous perfusion experiments with temperature and flow control under optical inspection. To describe the trap function, we present a mathematical and FEM-based COMSOL model for the acoustic mode that defines the nodal position of trapped objects in the spherical cavity aligned with the microscope field of view and depth of field. Continuous perfusion experiments were conducted in sterile conditions over 55 h with a K562 cell line, allowing for deterministic monitoring. The acoustofluidic platform allows for rational in vitro cell testing imitating in vivo conditions such as cell function tests or cell-cell interactions.
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Affiliation(s)
- Luca Fabiano
- Heinz-Nixdorf-Chair of Biomedical Electronics, School of Computation, Information and Technology, Technical University of Munich, TranslaTUM, 80333 Munich, Germany; (L.F.); (M.B.); (M.H.K.)
| | - Shilpi Pandey
- Heinz-Nixdorf-Chair of Biomedical Electronics, School of Computation, Information and Technology, Technical University of Munich, TranslaTUM, 80333 Munich, Germany; (L.F.); (M.B.); (M.H.K.)
| | - Martin Brischwein
- Heinz-Nixdorf-Chair of Biomedical Electronics, School of Computation, Information and Technology, Technical University of Munich, TranslaTUM, 80333 Munich, Germany; (L.F.); (M.B.); (M.H.K.)
| | - Morteza Hasanzadeh Kafshgari
- Heinz-Nixdorf-Chair of Biomedical Electronics, School of Computation, Information and Technology, Technical University of Munich, TranslaTUM, 80333 Munich, Germany; (L.F.); (M.B.); (M.H.K.)
- Central Institute for Translational Cancer Research (TranslaTUM), School of Medicine, Technical University of Munich, 80333 Munich, Germany
- Department of Radiation Oncology, School of Medicine, Technical University of Munich, 80333 Munich, Germany
| | - Oliver Hayden
- Heinz-Nixdorf-Chair of Biomedical Electronics, School of Computation, Information and Technology, Technical University of Munich, TranslaTUM, 80333 Munich, Germany; (L.F.); (M.B.); (M.H.K.)
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Salimian Rizi F, Talebi S, Manshadi MKD, Mohammadi M. Separation of bacteria smaller than 4 µm from other blood components using insulator-based dielectrophoresis: numerical simulation approach. Biomech Model Mechanobiol 2023; 22:825-836. [PMID: 36787033 DOI: 10.1007/s10237-022-01683-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 12/28/2022] [Indexed: 02/15/2023]
Abstract
Bloodstream infection (BSI) is a life-threatening infection that causes more than 80,000 deaths and more than 500,000 infections annually in North America. The rapid diagnosis of infection reduces BSI mortality. We proposed bacterial enrichment and separation approach in the current work that may reduce culturing time and accelerate the diagnosis of infection. Over the last two decades, multiple separation methods have been developed, and among these methods, insulator-based dielectrophoresis (iDEP) is considered a powerful technique for separating biological particles. Bacterial separation in the blood is challenging due to the presence of other blood cells, such as white blood cells, red blood cells, and platelets. In the present study, a model is presented which is capable of blood cells separation and directing each cell to a specific outlet using continuous flows of particles with sizes larger than 8 µm, 8-4 µm, and smaller than 4 µm. Compared to other methods, such as filtration, the main advantage of this model is that particles larger than 8 µm are separated from the flow before other particles, which prevents the accumulation of particles in the channel. The outcomes of simulations demonstrated that the factors such as applied voltage and channel dimensions significantly affect the separation efficiency. If these values are properly selected (for example voltage of 70 V that was causing an electric field of 200 V/cm), the proposed model can completely (100%) separate particles larger than 8 µm and smaller than 4 µm (8-4 µm particles separation efficiency is 95%).
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Affiliation(s)
| | - Shahram Talebi
- Mechanical Engineering Department, Yazd University, Yazd, Iran.
| | | | - Mehdi Mohammadi
- Department of Biological Sciences, University of Calgary, Calgary, AB, T2N 1N4, Canada.
- Department of Biomedical Engineering, University of Calgary, Calgary, AB, T2N 1N4, Canada.
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Abstract
Isotachophoresis (ITP) is a versatile electrophoretic technique that can be used for sample preconcentration, separation, purification, and mixing, and to control and accelerate chemical reactions. Although the basic technique is nearly a century old and widely used, there is a persistent need for an easily approachable, succinct, and rigorous review of ITP theory and analysis. This is important because the interest and adoption of the technique has grown over the last two decades, especially with its implementation in microfluidics and integration with on-chip chemical and biochemical assays. We here provide a review of ITP theory starting from physicochemical first-principles, including conservation of species, conservation of current, approximation of charge neutrality, pH equilibrium of weak electrolytes, and so-called regulating functions that govern transport dynamics, with a strong emphasis on steady and unsteady transport. We combine these generally applicable (to all types of ITP) theoretical discussions with applications of ITP in the field of microfluidic systems, particularly on-chip biochemical analyses. Our discussion includes principles that govern the ITP focusing of weak and strong electrolytes; ITP dynamics in peak and plateau modes; a review of simulation tools, experimental tools, and detection methods; applications of ITP for on-chip separations and trace analyte manipulation; and design considerations and challenges for microfluidic ITP systems. We conclude with remarks on possible future research directions. The intent of this review is to help make ITP analysis and design principles more accessible to the scientific and engineering communities and to provide a rigorous basis for the increased adoption of ITP in microfluidics.
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Affiliation(s)
- Ashwin Ramachandran
- Department of Aeronautics and Astronautics, Stanford University, Stanford, California 94305, United States
| | - Juan G Santiago
- Department of Mechanical Engineering, Stanford University, Stanford, California 94305, United States
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Li D, Yu W, Zhou T, Li M, Song Y, Li D. Conductivity-difference-enhanced DC dielectrophoretic particle separation in a microfluidic chip. Analyst 2022; 147:1106-1116. [DOI: 10.1039/d1an02196f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Conductivity-difference-enhanced DC dielectrophoretic particle separation in a microfluidic chip. Two immiscible electrolyte solutions with different conductivities in microchannels.
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Affiliation(s)
- Deyu Li
- Department of Marine Engineering, Dalian Maritime University, Dalian, 116026, China
| | - Weicheng Yu
- Department of Marine Engineering, Dalian Maritime University, Dalian, 116026, China
| | - Teng Zhou
- Mechanical and Electrical Engineering College, Hainan University, Hai Kou, 570228, China
| | - Mengqi Li
- Department of Marine Engineering, Dalian Maritime University, Dalian, 116026, China
| | - Yongxin Song
- Department of Marine Engineering, Dalian Maritime University, Dalian, 116026, China
| | - Dongqing Li
- Department of Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
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5
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Xuan X. Review of nonlinear electrokinetic flows in insulator-based dielectrophoresis: From induced charge to Joule heating effects. Electrophoresis 2021; 43:167-189. [PMID: 33991344 DOI: 10.1002/elps.202100090] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Revised: 05/08/2021] [Accepted: 05/11/2021] [Indexed: 01/03/2023]
Abstract
Insulator-based dielectrophoresis (iDEP) has been increasingly used for particle manipulation in various microfluidic applications. It exploits insulating structures to constrict and/or curve electric field lines to generate field gradients for particle dielectrophoresis. However, the presence of these insulators, especially those with sharp edges, causes two nonlinear electrokinetic flows, which, if sufficiently strong, may disturb the otherwise linear electrokinetic motion of particles and affect the iDEP performance. One is induced charge electroosmotic (ICEO) flow because of the polarization of the insulators, and the other is electrothermal flow because of the amplified Joule heating in the fluid around the insulators. Both flows vary nonlinearly with the applied electric field (either DC or AC) and exhibit in the form of fluid vortices, which have been utilized to promote some applications while being suppressed in others. The effectiveness of iDEP benefits from a comprehensive understanding of the nonlinear electrokinetic flows, which is complicated by the involvement of the entire iDEP device into electric polarization and thermal diffusion. This article is aimed to review the works on both the fundamentals and applications of ICEO and electrothermal flows in iDEP microdevices. A personal perspective of some future research directions in the field is also given.
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Affiliation(s)
- Xiangchun Xuan
- Department of Mechanical Engineering, Clemson University, Clemson, South Carolina, USA
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Riley KR, El Hadri H, Tan J, Hackley VA, MacCrehan WA. High separation efficiency of gold nanomaterials of different aspect ratio and size using capillary transient isotachophoresis. J Chromatogr A 2019; 1598:216-222. [PMID: 30948041 DOI: 10.1016/j.chroma.2019.03.054] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 03/17/2019] [Accepted: 03/23/2019] [Indexed: 11/25/2022]
Abstract
Two modes of capillary electrophoresis (CE), capillary zone electrophoresis (CZE) and capillary transient isotachophoresis (ctITP), were compared for the detection and separation of spherical gold nanoparticles (AuNPs) and gold nanorods (AuNRs). The development of ctITP using two different leading ions is described. Overall, when compared to traditional capillary zone electrophoresis (CZE), ctITP resulted in improved peak shape and peak efficiency. Specifically, the number of theoretical plates for AuNR samples increased by a factor of 2-2.5 depending on the choice of leading ion. Further, using ctITP two AuNRs differing by aspect ratio were baseline resolved, whereas the same AuNRs could not be separated using CZE or other techniques like single particle inductively coupled plasma mass spectrometry (spICP-MS) and asymmetric flow field-flow fractionation (AF4). The results of this study demonstrate that ctITP is an efficient on-line technique for the improved detection and separation of gold nanomaterials in CE.
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Affiliation(s)
- Kathryn R Riley
- National Institute of Standards and Technology, Material Measurement Laboratory - Chemical Sciences Division, 100 Bureau Drive, Gaithersburg, MD, 20899, USA.
| | - Hind El Hadri
- National Institute of Standards and Technology, Material Measurement Laboratory - Materials Measurement Science Division, 100 Bureau Drive, Gaithersburg, MD, 20899, USA
| | - Jiaojie Tan
- National Institute of Standards and Technology, Material Measurement Laboratory - Materials Measurement Science Division, 100 Bureau Drive, Gaithersburg, MD, 20899, USA
| | - Vincent A Hackley
- National Institute of Standards and Technology, Material Measurement Laboratory - Materials Measurement Science Division, 100 Bureau Drive, Gaithersburg, MD, 20899, USA
| | - William A MacCrehan
- National Institute of Standards and Technology, Material Measurement Laboratory - Chemical Sciences Division, 100 Bureau Drive, Gaithersburg, MD, 20899, USA
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Song L, Yu L, Zhou Y, Antao AR, Prabhakaran RA, Xuan X. Electrokinetic instability in microchannel ferrofluid/water co-flows. Sci Rep 2017; 7:46510. [PMID: 28406228 PMCID: PMC5390253 DOI: 10.1038/srep46510] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 03/17/2017] [Indexed: 12/30/2022] Open
Abstract
Electrokinetic instability refers to unstable electric field-driven disturbance to fluid flows, which can be harnessed to promote mixing for various electrokinetic microfluidic applications. This work presents a combined numerical and experimental study of electrokinetic ferrofluid/water co-flows in microchannels of various depths. Instability waves are observed at the ferrofluid and water interface when the applied DC electric field is beyond a threshold value. They are generated by the electric body force that acts on the free charge induced by the mismatch of ferrofluid and water electric conductivities. A nonlinear depth-averaged numerical model is developed to understand and simulate the interfacial electrokinetic behaviors. It considers the top and bottom channel walls’ stabilizing effects on electrokinetic flow through the depth averaging of three-dimensional transport equations in a second-order asymptotic analysis. This model is found accurate to predict both the observed electrokinetic instability patterns and the measured threshold electric fields for ferrofluids of different concentrations in shallow microchannels.
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Affiliation(s)
- Le Song
- School of Instrument Science and Opto-electronic Engineering, Hefei University of Technology, Hefei 230009, China
| | - Liandong Yu
- School of Instrument Science and Opto-electronic Engineering, Hefei University of Technology, Hefei 230009, China
| | - Yilong Zhou
- Department of Mechanical Engineering, Clemson University, Clemson, SC 29634-0921, USA
| | - Asher Reginald Antao
- Department of Mechanical Engineering, Clemson University, Clemson, SC 29634-0921, USA
| | | | - Xiangchun Xuan
- Department of Mechanical Engineering, Clemson University, Clemson, SC 29634-0921, USA
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8
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Using capillary electrophoresis to characterize polymeric particles. J Chromatogr A 2016; 1463:169-75. [PMID: 27543386 DOI: 10.1016/j.chroma.2016.08.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 08/08/2016] [Accepted: 08/08/2016] [Indexed: 01/16/2023]
Abstract
Capillary electrophoresis (CE) was used for the characterization of a variety of polymeric micron and sub-micron particles based on size, surface functionality, and binding properties. First, a robust capillary zone electrophoresis (CZE) method was developed for the baseline separation and quantitation of commercially available polystyrene particles with various surface modifications (including amino, carboxylate, and sulfate functional groups) and various sizes (0.2, 0.5, 1.0, and 3.0μm). The separation of DNA-templated polyacrylamide particles from untemplated particles (as used for the Ion Torrent Personal Genome Machine) was demonstrated. Finally, using the 29-base thrombin aptamer and thrombin protein as a model system, a study was undertaken to determine dissociation constants for the aptamer and protein in free solution and when the aptamer was conjugated to a particle, with the goal of better understanding how the use of solid substrates, like particles, affects selection and binding processes. Dissociation constants were determined and were found to be approximately 5-fold higher for the aptamer conjugated to a particle relative to that in free solution.
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Praus P, Turicová M, Suchomel P, Kvítek L. Capillary isotachophoresis for separation of silver nanoparticles according to size. RSC Adv 2015. [DOI: 10.1039/c5ra10676a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Capillary isotachophoresis was used for the separation of Ag nanoparticles stabilized by gelatin according to their size.
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Affiliation(s)
- Petr Praus
- Department of Chemistry
- VŠB-Technical University of Ostrava
- 708 33 Ostrava-Poruba
- Czech Republic
- Institute of Environmental Technology
| | - Martina Turicová
- Department of Chemistry
- VŠB-Technical University of Ostrava
- 708 33 Ostrava-Poruba
- Czech Republic
| | - Petr Suchomel
- Department of Physical Chemistry
- Palacký University
- 771 46 Olomouc
- Czech Republic
| | - Libor Kvítek
- Department of Physical Chemistry
- Palacký University
- 771 46 Olomouc
- Czech Republic
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10
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Shintaku H, Palko JW, Sanders GM, Santiago JG. Increasing Hybridization Rate and Sensitivity of Bead-Based Assays Using Isotachophoresis. Angew Chem Int Ed Engl 2014; 53:13813-6. [DOI: 10.1002/anie.201408403] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Indexed: 12/25/2022]
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11
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Shintaku H, Palko JW, Sanders GM, Santiago JG. Increasing Hybridization Rate and Sensitivity of Bead-Based Assays Using Isotachophoresis. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201408403] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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13
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Khnouf R, Goet G, Baier T, Hardt S. Increasing the sensitivity of microfluidics based immunoassays using isotachophoresis. Analyst 2014; 139:4564-71. [DOI: 10.1039/c4an00545g] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Strychalski EA, Konek C, Butts ELR, Vallone PM, Henry AC, Ross D. DNA purification from crude samples for human identification using gradient elution isotachophoresis. Electrophoresis 2013; 34:2522-30. [DOI: 10.1002/elps.201300133] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Revised: 05/17/2013] [Accepted: 05/22/2013] [Indexed: 01/31/2023]
Affiliation(s)
- Elizabeth A. Strychalski
- Material Measurement Laboratory; National Institute of Standards and Technology; Gaithersburg MD USA
| | | | - Erica L. R. Butts
- Material Measurement Laboratory; National Institute of Standards and Technology; Gaithersburg MD USA
| | - Peter M. Vallone
- Material Measurement Laboratory; National Institute of Standards and Technology; Gaithersburg MD USA
| | - Alyssa C. Henry
- Applied Research Associates; Incorporated; Alexandria VA USA
| | - David Ross
- Material Measurement Laboratory; National Institute of Standards and Technology; Gaithersburg MD USA
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15
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Goet G, Baier T, Hardt S, Sen AK. Isotachophoresis with emulsions. BIOMICROFLUIDICS 2013; 7:44103. [PMID: 24404037 PMCID: PMC3732298 DOI: 10.1063/1.4816347] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Accepted: 07/09/2013] [Indexed: 05/16/2023]
Abstract
An experimental study on isotachophoresis (ITP) in which an emulsion is used as leading electrolyte (LE) is reported. The study aims at giving an overview about the transport and flow phenomena occurring in that context. Generally, it is observed that the oil droplets initially dispersed in the LE are collected at the ITP transition zone and advected along with it. The detailed behavior at the transition zone depends on whether or not surfactants (polyvinylpyrrolidon, PVP) are added to the electrolytes. In a system without surfactants, coalescence is observed between the droplets collected at the ITP transition zone. After having achieved a certain size, the droplets merge with the channel walls, leaving an oil film behind. In systems with PVP, coalescence is largely suppressed and no merging of droplets with the channel walls is observed. Instead, at the ITP transition zone, a droplet agglomerate of increasing size is formed. In the initial stages of the ITP experiments, two counter rotating vortices are formed inside the terminating electrolyte. The vortex formation is qualitatively explained based on a hydrodynamic instability triggered by fluctuations of the number density of oil droplets.
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Affiliation(s)
- G Goet
- Institute for Nano- and Microfluidics, Center of Smart Interfaces, TU Darmstadt, 64287 Darmstadt, Germany
| | - T Baier
- Institute for Nano- and Microfluidics, Center of Smart Interfaces, TU Darmstadt, 64287 Darmstadt, Germany
| | - S Hardt
- Institute for Nano- and Microfluidics, Center of Smart Interfaces, TU Darmstadt, 64287 Darmstadt, Germany
| | - A K Sen
- Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036, India
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Preconcentration of 3-nitrotyrosine in urine by transient isotachophoresis in MEKC. J Pharm Biomed Anal 2013; 78-79:100-4. [DOI: 10.1016/j.jpba.2013.02.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Revised: 01/30/2013] [Accepted: 02/04/2013] [Indexed: 11/19/2022]
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17
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Malá Z, Gebauer P, Boček P. Recent progress in analytical capillary isotachophoresis. Electrophoresis 2012; 34:19-28. [DOI: 10.1002/elps.201200323] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Revised: 07/23/2012] [Accepted: 07/23/2012] [Indexed: 12/18/2022]
Affiliation(s)
- Zdena Malá
- Institute of Analytical Chemistry; Academy of Sciences of the Czech Republic; Brno; Czech Republic
| | - Petr Gebauer
- Institute of Analytical Chemistry; Academy of Sciences of the Czech Republic; Brno; Czech Republic
| | - Petr Boček
- Institute of Analytical Chemistry; Academy of Sciences of the Czech Republic; Brno; Czech Republic
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Donolato M, Dalslet BT, Hansen MF. Microstripes for transport and separation of magnetic particles. BIOMICROFLUIDICS 2012; 6:24110-241106. [PMID: 22655020 PMCID: PMC3360724 DOI: 10.1063/1.4704520] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Accepted: 03/28/2012] [Indexed: 05/08/2023]
Abstract
We present a simple technique for creating an on-chip magnetic particle conveyor based on exchange-biased permalloy microstripes. The particle transportation relies on an array of stripes with a spacing smaller than their width in conjunction with a periodic sequence of four different externally applied magnetic fields. We demonstrate the controlled transportation of a large population of particles over several millimeters of distance as well as the spatial separation of two populations of magnetic particles with different magnetophoretic mobilities. The technique can be used for the controlled selective manipulation and separation of magnetically labelled species.
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Zhu J, Xuan X. Curvature-induced dielectrophoresis for continuous separation of particles by charge in spiral microchannels. BIOMICROFLUIDICS 2011; 5:24111. [PMID: 21792385 PMCID: PMC3143671 DOI: 10.1063/1.3599883] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2011] [Accepted: 05/21/2011] [Indexed: 05/07/2023]
Abstract
The separation of particles from a heterogeneous mixture is critical in chemical and biological analyses. Many methods have been developed to separate particles in microfluidic devices. However, the majority of these separations have been limited to be size based and binary. We demonstrate herein a continuous dc electric field driven separation of carboxyl-coated and noncoated 10 μm polystyrene beads by charge in a double-spiral microchannel. This method exploits the inherent electric field gradients formed within the channel turns to manipulate particles by dielectrophoresis and is thus termed curvature-induced dielectrophoresis. The spiral microchannel is also demonstrated to continuously sort noncoated 5 μm beads, noncoated 10 μm beads, and carboxyl-coated 10 μm beads into different collecting wells by charge and size simultaneously. The observed particle separation processes in different situations are all predicted with reasonable agreements by a numerical model. This curvature-induced dielectrophoresis technique eliminates the in-channel microelectrodes and obstacles that are required in traditional electrode- and insulator-based dielectrophoresis devices. It may potentially be used to separate multiple particle targets by intrinsic properties for lab-on-a-chip applications.
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Affiliation(s)
- Junjie Zhu
- Department of Mechanical Engineering, Clemson University, Clemson, South Carolina 29634-0921, USA
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