1
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Tabarhoseini SM, Kale AS, Koniers PM, Boone AC, Bentor J, Boies A, Zhao H, Xuan X. Charge-Based Separation of Microparticles Using AC Insulator-Based Dielectrophoresis. Anal Chem 2024; 96:13672-13678. [PMID: 39126704 DOI: 10.1021/acs.analchem.4c02646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/12/2024]
Abstract
Surface charge is an important property of particles. It has been utilized to separate particles in microfluidic devices, where dielectrophoresis (DEP) is often the driving force. However, current DEP-based particle separations based on the charge differences work only for particles of similar sizes. They become less effective and may even fail for a mixture of particles differing in both charge and size. We demonstrate that our recently developed AC insulator-based dielectrophoresis (AC iDEP) technique can direct microparticles toward charge-dependent equilibrium positions in a ratchet microchannel. Such charge-based particle separation is controlled by the imposed AC voltage frequency and amplitude but is nearly unaffected by the size of either type of particle in the mixture except for the time required to achieve an effective separation. This AC iDEP technique may potentially be used to focus and separate submicron or even nanoparticles because of its virtually "infinite" channel length.
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Affiliation(s)
| | - Akshay Shridhar Kale
- Department of Engineering, University of Cambridge, Cambridge, CB2 1PZ, United Kingdom
| | - Peter Michael Koniers
- Department of Mechanical Engineering, Clemson University, Clemson, South Carolina 29634, United States
| | - Anna Claire Boone
- Department of Mechanical Engineering, Clemson University, Clemson, South Carolina 29634, United States
| | - Joseph Bentor
- Department of Mechanical Engineering, Clemson University, Clemson, South Carolina 29634, United States
| | - Adam Boies
- Department of Engineering, University of Cambridge, Cambridge, CB2 1PZ, United Kingdom
| | - Hui Zhao
- Department of Mechanical Engineering, University of Nevada, Las Vegas, Nevada 89154, United States
| | - Xiangchun Xuan
- Department of Mechanical Engineering, Clemson University, Clemson, South Carolina 29634, United States
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2
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Welden R, Das A, Krause S, Schöning MJ, Wagner PH, Wagner T. Actively Driven Light-Addressable Sensor/Actuator System for Automated pH Control for the Integration in Lab-On-A-Chip (LoC) Platforms. ACS Sens 2024; 9:1533-1544. [PMID: 38445576 DOI: 10.1021/acssensors.3c02712] [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] [Indexed: 03/07/2024]
Abstract
The miniaturization of microfluidic systems usually comes at the cost of more difficult integration of sensors and actuators inside the channel. As an alternative, this work demonstrates the embedding of semiconductor-based sensor and actuator technologies that can be spatially and temporally controlled from outside the channel using light. The first element is a light-addressable potentiometric sensor, consisting of an Al/Si/SiO2/Si3N4 structure, that can measure pH changes at the Si3N4/electrolyte interface. The pH value is a crucial factor in biological and chemical systems, and besides measuring, it is often important to bring the system out of equilibrium or to adjust and control precisely the surrounding medium. This can be done photoelectrocatalytically by utilizing light-addressable electrodes. These consist of a glass/SnO2:F/TiO2 structure, whereby direct charge transfer between the TiO2 and the electrolyte leads to a pH change upon irradiation. To complement the advantages of both, we integrated a light-addressable sensor with a pH sensitivity of 41.5 mV·pH-1 and a light-addressable electrode into a microfluidic setup. Here, we demonstrated a simultaneous operation with the ability to generate and record pH gradients inside a channel under static and dynamic flow conditions. The results show that dependent on the light-addressable electrode (LAE)-illumination conditions, pH changes up to ΔpH of 2.75 and of 3.52 under static and dynamic conditions, respectively, were spatially monitored by the light-addressable potentiometric sensor. After flushing with fresh buffer solution, the pH returned to its initial value. Depending on the LAE illumination, pH gradients with a maximum pH change of ΔpH of 1.42 were tailored perpendicular to the flow direction. In a final experiment, synchronous LAE illumination led to a stepwise increase in the pH inside the channel.
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Affiliation(s)
- Rene Welden
- Institute of Nano- and Biotechnologies (INB), Aachen University of Applied Sciences, Heinrich-Mußmann-Str. 1, Jülich 52428, Germany
- Laboratory for Soft Matter and Biophysics, KU Leuven, Celestijnenlaan 200D, Leuven 3001, Belgium
| | - Anirban Das
- School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London E1 4NS, U.K
| | - Steffi Krause
- School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London E1 4NS, U.K
| | - Michael J Schöning
- Institute of Nano- and Biotechnologies (INB), Aachen University of Applied Sciences, Heinrich-Mußmann-Str. 1, Jülich 52428, Germany
- Institute of Biological Information Processing (IBI-3), Forschungszentrum Jülich GmbH, Jülich 52428, Germany
| | - Patrick H Wagner
- Institute of Nano- and Biotechnologies (INB), Aachen University of Applied Sciences, Heinrich-Mußmann-Str. 1, Jülich 52428, Germany
- Laboratory for Soft Matter and Biophysics, KU Leuven, Celestijnenlaan 200D, Leuven 3001, Belgium
| | - Torsten Wagner
- Institute of Nano- and Biotechnologies (INB), Aachen University of Applied Sciences, Heinrich-Mußmann-Str. 1, Jülich 52428, Germany
- Institute of Biological Information Processing (IBI-3), Forschungszentrum Jülich GmbH, Jülich 52428, Germany
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3
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Haensch T, Zitzmann FD, Jahnke HG, Blaha ME, Paternoga E, Zeitler K, Belder D, Robitzki AA. Integration of Impedimetric Sensors for In Situ Electrochemical Impedance Spectroscopy in Free-Flow Electrophoresis Applications in Lab-on-Chip Systems. ACS Sens 2022; 7:3906-3914. [PMID: 36512685 DOI: 10.1021/acssensors.2c01938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Miniaturization and integration of chemical reactions into fluidic systems in combination with product purification or buffer exchange can reduce the amount of solvents and reactants required while increasing synthesis efficiency. A critical step is the regulation of flow rates to realize optimal synthesis conditions and high purification rates, so real-time, label-free monitoring is required in methods such as free-flow electrophoresis. Optical detection methods are widely used, but they often have complex excitation and detection setups that are disadvantageous for point-of-care applications. The method we have chosen is electrochemical impedance spectroscopy for detecting charged compounds in aqueous buffers with low ionic strength. Propranolol was selected for proof of concept and was separated from the organic solvent and the precursor oxirane by free-flow electrophoresis. For this purpose, electrode structures were fabricated in microfluidic channels by photolithographic lift-off technique and optimized in terms of positioning, electrode size and distance for sensitive detection, and quantification of propranolol in the nanomolar range. It is also noteworthy that the organic solvent dimethyl sulfoxide (DMSO) could be detected and quantified by an increased impedance magnitude. Subsequently, the optimized interdigital electrode structures were integrated into the outlet channels of the electrophoretic separation chamber to monitor the various outgoing fluidic streams and provide in-line control of the fluidic flows for the purification step. In conclusion, we can provide a microfluidic chip to monitor the separation efficiency of a substance mixture during free-flow electrophoresis without the need of complex analytical techniques using electrochemical impedance spectroscopy.
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Affiliation(s)
- Tobias Haensch
- Institute of Biochemistry, Center for Biomedicine and Biotechnology, Molecular Biologic-Biochemical Processing Technology, Leipzig University, Deutscher Platz 5, 04103 Leipzig, Germany
| | - Franziska D Zitzmann
- Institute of Biochemistry, Center for Biomedicine and Biotechnology, Molecular Biologic-Biochemical Processing Technology, Leipzig University, Deutscher Platz 5, 04103 Leipzig, Germany
| | - Heinz-Georg Jahnke
- Institute of Biochemistry, Center for Biomedicine and Biotechnology, Molecular Biologic-Biochemical Processing Technology, Leipzig University, Deutscher Platz 5, 04103 Leipzig, Germany
| | - Maximilian E Blaha
- Institute of Analytical Chemistry, Leipzig University, Technikum Analytikum, Linnéstr. 3, 04103 Leipzig, Germany
| | - Erik Paternoga
- Institute of Organic Chemistry, Leipzig University, Johannisallee 29, 04103 Leipzig, Germany
| | - Kirsten Zeitler
- Institute of Organic Chemistry, Leipzig University, Johannisallee 29, 04103 Leipzig, Germany
| | - Detlev Belder
- Institute of Analytical Chemistry, Leipzig University, Technikum Analytikum, Linnéstr. 3, 04103 Leipzig, Germany
| | - Andrea A Robitzki
- Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, Eggenstein-Leopoldshafen, 76344 Karlsruhe, Germany
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4
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Courtney M, Glawdel T, Ren CL. Investigating peak dispersion in free-flow counterflow gradient focusing due to electroosmotic flow. Electrophoresis 2022; 44:646-655. [PMID: 36502493 DOI: 10.1002/elps.202200230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 11/09/2022] [Accepted: 11/24/2022] [Indexed: 12/14/2022]
Abstract
Free-flow electrophoresis (FFE) has the ability to continuously separate charged solutes from complex biological mixtures. Recently, a free-flow counterflow gradient focusing mechanism has been introduced to FFE, and it offers the potential for improved resolution and versatility. However, further investigation is needed to understand the solute dispersion at the focal position. Therefore, the goal of this work is to model the impact of electroosmotic flow, which is found to produce a pressure-driven backflow to maintain the fixed counterflow inputs. Like the counterflow, this backflow has a parabolic velocity profile that must be considered when predicting the concentration distribution of a given solute. After the model is established, preliminary experimental results are presented for a qualitative comparison. Results demonstrate a reasonable agreement at low applied voltages and provide a strong framework for future experimental validation.
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Affiliation(s)
- Matthew Courtney
- Department of Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo, Ontario, Canada
| | - Tomasz Glawdel
- Department of Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo, Ontario, Canada
| | - Carolyn L Ren
- Department of Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo, Ontario, Canada
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5
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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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6
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Couceiro P, Alonso-Chamarro J. Fluorescence Imaging Characterization of the Separation Process in a Monolithic Microfluidic Free-Flow Electrophoresis Device Fabricated Using Low-Temperature Co-Fired Ceramics. MICROMACHINES 2022; 13:mi13071023. [PMID: 35888840 PMCID: PMC9324176 DOI: 10.3390/mi13071023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 06/22/2022] [Accepted: 06/24/2022] [Indexed: 11/26/2022]
Abstract
A monolithic microfluidic free-flow electrophoresis device, fabricated using low-temperature co-fired ceramic technology, is presented. The device integrates gold electrodes and a 20 µm thick transparent ceramic optical window, suitable for fluorescence imaging, into a multilevel microfluidic chamber design. The microfluidic chamber consists of a 60 µm deep separation chamber and two, 50 µm deep electrode chambers separated by 10 µm deep side channel arrays. Fluorescence imaging was used for in-chip, spatial-temporal characterization of local pH variations in separation conditions as well as to characterize the separation process. The device allowed baseline resolution separation of a sample mixture of Fluorescein, Rhodamine 6G, and 4-Methylumbelliferone at pH 7.0, in only 6 s, using 378 V.s/cm. The results demonstrate the possibility of studying a chemical process using fluorescence imaging within the traditional fields of low-temperature co-fired ceramics technology, such as high-electrical-field applications, while using a simple fabrication procedure suitable for low-cost mass production.
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7
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Liu Y, Huang Y, Wu M, Kong S, Cao W, Li S, Yan G, Liu B, Yang P, Zhang Q, Qiao L, Shen H. Microfluidic free‐flow paper electrochromatography for continuous separation of glycans. ChemElectroChem 2022. [DOI: 10.1002/celc.202200106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Yingchao Liu
- Fudan University Institutes of Biomedical Sciences CHINA
| | - Yuanyu Huang
- Fudan University Institutes of Biomedical Sciences CHINA
| | - Mengxi Wu
- Fudan University Institutes of Biomedical Sciences CHINA
| | - Siyuan Kong
- Fudan University Institutes of Biomedical Sciences CHINA
| | - Weiqian Cao
- Fudan University Institutes of Biomedical Sciences CHINA
| | - Shunxiang Li
- Fudan University Institutes of Biomedical Sciences CHINA
| | - Guoqun Yan
- Fudan University Institutes of Biomedical Sciences CHINA
| | | | - Pengyuan Yang
- Fudan University Institutes of Biomedical Sciences CHINA
| | - Quanqing Zhang
- University of California Riverside Chemistry UNITED STATES
| | - Liang Qiao
- Fudan University Chemistry Songhu Road 2005 200438 Shanghai CHINA
| | - Huali Shen
- Fudan University Institutes of Biomedical Sciences CHINA
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8
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Panneerselvam R, Sadat H, Höhn EM, Das A, Noothalapati H, Belder D. Microfluidics and surface-enhanced Raman spectroscopy, a win-win combination? LAB ON A CHIP 2022; 22:665-682. [PMID: 35107464 DOI: 10.1039/d1lc01097b] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
With the continuous development in nanoscience and nanotechnology, analytical techniques like surface-enhanced Raman spectroscopy (SERS) render structural and chemical information of a variety of analyte molecules in ultra-low concentration. Although this technique is making significant progress in various fields, the reproducibility of SERS measurements and sensitivity towards small molecules are still daunting challenges. In this regard, microfluidic surface-enhanced Raman spectroscopy (MF-SERS) is well on its way to join the toolbox of analytical chemists. This review article explains how MF-SERS is becoming a powerful tool in analytical chemistry. We critically present the developments in SERS substrates for microfluidic devices and how these substrates in microfluidic channels can improve the SERS sensitivity, reproducibility, and detection limit. We then introduce the building materials for microfluidic platforms and their types such as droplet, centrifugal, and digital microfluidics. Finally, we enumerate some challenges and future directions in microfluidic SERS. Overall, this article showcases the potential and versatility of microfluidic SERS in overcoming the inherent issues in the SERS technique and also discusses the advantage of adding SERS to the arsenal of microfluidics.
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Affiliation(s)
- Rajapandiyan Panneerselvam
- Institute of Analytical Chemistry, Leipzig University, Linnéstraße 3, 04103 Leipzig, Germany
- Department of Chemistry, SRM University AP, Amaravati, Andhra Pradesh 522502, India.
| | - Hasan Sadat
- Institute of Analytical Chemistry, Leipzig University, Linnéstraße 3, 04103 Leipzig, Germany
| | - Eva-Maria Höhn
- Institute of Analytical Chemistry, Leipzig University, Linnéstraße 3, 04103 Leipzig, Germany
| | - Anish Das
- Institute of Analytical Chemistry, Leipzig University, Linnéstraße 3, 04103 Leipzig, Germany
| | - Hemanth Noothalapati
- Faculty of Life and Environmental Sciences, Shimane University, Matsue, Japan
- Raman Project Center for Medical and Biological Applications, Shimane University, Matsue, Japan
| | - Detlev Belder
- Institute of Analytical Chemistry, Leipzig University, Linnéstraße 3, 04103 Leipzig, Germany
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9
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Zhang A, Xu J, Li X, Lin Z, Song Y, Li X, Wang Z, Cheng Y. High-Throughput Continuous-Flow Separation in a Micro Free-Flow Electrophoresis Glass Chip Based on Laser Microfabrication. SENSORS (BASEL, SWITZERLAND) 2022; 22:1124. [PMID: 35161869 PMCID: PMC8838507 DOI: 10.3390/s22031124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 01/20/2022] [Accepted: 01/28/2022] [Indexed: 06/14/2023]
Abstract
Micro free-flow electrophoresis (μFFE) provides a rapid and straightforward route for the high-performance online separation and purification of targeted liquid samples in a mild manner. However, the facile fabrication of a μFFE device with high throughput and high stability remains a challenge due to the technical barriers of electrode integration and structural design for the removal of bubbles for conventional methods. To address this, the design and fabrication of a high-throughput μFFE chip are proposed using laser-assisted chemical etching of glass followed by electrode integration and subsequent low-temperature bonding. The careful design of the height ratio of the separation chamber and electrode channels combined with a high flow rate of buffer solution allows the efficient removal of electrolysis-generated bubbles along the deep electrode channels during continuous-flow separation. The introduction of microchannel arrays further enhances the stability of on-chip high-throughput separation. As a proof-of-concept, high-performance purification of fluorescein sodium solution with a separation purity of ~97.9% at a voltage of 250 V from the mixture sample solution of fluorescein sodium and rhodamine 6G solution is demonstrated.
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Affiliation(s)
- Aodong Zhang
- Engineering Research Center for Nanophotonics and Advanced Instrument, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China; (A.Z.); (Z.W.); (Y.C.)
- State Key Laboratory of Precision Spectroscopy, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China; (X.L.); (Z.L.); (Y.S.)
- XXL—The Extreme Optoelectromechanics Laboratory, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China
| | - Jian Xu
- Engineering Research Center for Nanophotonics and Advanced Instrument, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China; (A.Z.); (Z.W.); (Y.C.)
- State Key Laboratory of Precision Spectroscopy, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China; (X.L.); (Z.L.); (Y.S.)
- XXL—The Extreme Optoelectromechanics Laboratory, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China
| | - Xiaolong Li
- State Key Laboratory of Precision Spectroscopy, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China; (X.L.); (Z.L.); (Y.S.)
- XXL—The Extreme Optoelectromechanics Laboratory, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China
| | - Zijie Lin
- State Key Laboratory of Precision Spectroscopy, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China; (X.L.); (Z.L.); (Y.S.)
- XXL—The Extreme Optoelectromechanics Laboratory, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China
| | - Yunpeng Song
- State Key Laboratory of Precision Spectroscopy, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China; (X.L.); (Z.L.); (Y.S.)
- XXL—The Extreme Optoelectromechanics Laboratory, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China
| | - Xin Li
- Engineering Research Center for Nanophotonics and Advanced Instrument, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China; (A.Z.); (Z.W.); (Y.C.)
| | - Zhenhua Wang
- Engineering Research Center for Nanophotonics and Advanced Instrument, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China; (A.Z.); (Z.W.); (Y.C.)
- State Key Laboratory of Precision Spectroscopy, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China; (X.L.); (Z.L.); (Y.S.)
- XXL—The Extreme Optoelectromechanics Laboratory, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China
| | - Ya Cheng
- Engineering Research Center for Nanophotonics and Advanced Instrument, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China; (A.Z.); (Z.W.); (Y.C.)
- State Key Laboratory of Precision Spectroscopy, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China; (X.L.); (Z.L.); (Y.S.)
- XXL—The Extreme Optoelectromechanics Laboratory, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China
- State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
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10
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Duša F, Šalplachta J, Horká M, Lunerová K, Rosenbergová K, Kubíček O. Novel chip-based isoelectric focusing device for fractionation of bacteria prior to their mass spectrometry identification. Anal Chim Acta 2022; 1192:339333. [DOI: 10.1016/j.aca.2021.339333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 11/23/2021] [Accepted: 11/25/2021] [Indexed: 11/01/2022]
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11
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Microfluidic free-flow electrophoresis: a promising tool for protein purification and analysis in proteomics. J IND ENG CHEM 2022. [DOI: 10.1016/j.jiec.2022.02.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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12
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Arter WE, Saar KL, Herling TW, Knowles TPJ. Microchip Free-Flow Electrophoresis for Bioanalysis, Sensing, and Purification. Methods Mol Biol 2022; 2394:249-266. [PMID: 35094333 DOI: 10.1007/978-1-0716-1811-0_16] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The separation of complex mixtures is ubiquitous throughout molecular biology, and techniques such as gel-based electrophoresis are common laboratory practice. Such methods are not without their drawbacks, however, which include non-specific interactions between analyte and the separation matrix, poor yields in purification and non-continuous analyte throughput. Microfluidic techniques, which exploit physical phenomena unique to the microscale, promise to improve many aspects of traditional laboratory procedures. These methods offer a quantitative, solution-based alternative to traditional gel electrophoresis, with rapid measurement times enabling the analysis of transient or weak biomolecular interactions that would be challenging to observe with traditional methods. Here, we present a protocol for the lithographic fabrication and operation of microfluidic chips capable of free-flow electrophoretic (FFE) fractionation and analysis of biological analytes. We demonstrate the efficacy of our approach through a protein-sensing methodology based on FFE fractionation of DNA-protein mixtures. In addition, the FFE technique described here can be readily adapted to suit a variety of preparative and analytical applications, providing information on the charge, zeta-potential, and interactions of analytes.
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Affiliation(s)
- William E Arter
- Department of Chemistry, University of Cambridge, Cambridge, UK
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
| | - Kadi L Saar
- Department of Chemistry, University of Cambridge, Cambridge, UK
| | | | - Tuomas P J Knowles
- Department of Chemistry, University of Cambridge, Cambridge, UK.
- Cavendish Laboratory, University of Cambridge, Cambridge, UK.
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13
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Jender M, Höving S, Novo P, Freier E, Janasek D. Coupling Miniaturized Free-Flow Electrophoresis to Mass Spectrometry via a Multi-Emitter ESI Interface. Anal Chem 2021; 93:7204-7209. [PMID: 33939916 DOI: 10.1021/acs.analchem.1c00200] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We present a novel multi-emitter electrospray ionization (ESI) interface for the coupling of microfluidic free-flow electrophoresis (μFFE) with mass spectrometry (MS). The effluents of the μFFE outlets are analyzed in near real-time, allowing a direct optimization of the electrophoretic separation and an online monitoring of qualitative sample compositions. The short measurement time of just a few seconds for all outlets even enables a reasonable time-dependent monitoring. As a proof of concept, we employ the multi-emitter ESI interface for the continuous identification of analytes at 15 μFFE outlets via MS to optimize the μFFE separation of important players of cellular respiration in operando. The results indicate great potential of the presented system in downstream processing control, for example, for the monitoring and purification of products in continuous-flow microreactors.
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Affiliation(s)
- Matthias Jender
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Bunsen-Kirchhoff-Str. 11, 44139 Dortmund, Germany
| | - Stefan Höving
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Bunsen-Kirchhoff-Str. 11, 44139 Dortmund, Germany
| | - Pedro Novo
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Bunsen-Kirchhoff-Str. 11, 44139 Dortmund, Germany
| | - Erik Freier
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Bunsen-Kirchhoff-Str. 11, 44139 Dortmund, Germany
| | - Dirk Janasek
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Bunsen-Kirchhoff-Str. 11, 44139 Dortmund, Germany
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14
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Preuss JA, Nguyen GN, Berk V, Bahnemann J. Miniaturized free-flow electrophoresis: production, optimization, and application using 3D printing technology. Electrophoresis 2020; 42:305-314. [PMID: 33128392 DOI: 10.1002/elps.202000149] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 10/22/2020] [Accepted: 10/25/2020] [Indexed: 12/11/2022]
Abstract
The increasing resolution of three-dimensional (3D) printing offers simplified access to, and development of, microfluidic devices with complex 3D structures. Therefore, this technology is increasingly used for rapid prototyping in laboratories and industry. Microfluidic free flow electrophoresis (μFFE) is a versatile tool to separate and concentrate different samples (such as DNA, proteins, and cells) to different outlets in a time range measured in mere tens of seconds and offers great potential for use in downstream processing, for example. However, the production of μFFE devices is usually rather elaborate. Many designs are based on chemical pretreatment or manual alignment for the setup. Especially for the separation chamber of a μFFE device, this is a crucial step which should be automatized. We have developed a smart 3D design of a μFFE to pave the way for a simpler production. This study presents (1) a robust and reproducible way to build up critical parts of a μFFE device based on high-resolution MultiJet 3D printing; (2) a simplified insertion of commercial polycarbonate membranes to segregate separation and electrode chambers; and (3) integrated, 3D-printed wells that enable a defined sample fractionation (chip-to-world interface). In proof of concept experiments both a mixture of fluorescence dyes and a mixture of amino acids were successfully separated in our 3D-printed μFFE device.
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Affiliation(s)
- John-Alexander Preuss
- Institute of Technical Chemistry, Leibniz University Hannover, Callinstraße 5, Hannover, 30167, Germany
| | - Gia Nam Nguyen
- Institute of Technical Chemistry, Leibniz University Hannover, Callinstraße 5, Hannover, 30167, Germany
| | - Virginia Berk
- Institute of Technical Chemistry, Leibniz University Hannover, Callinstraße 5, Hannover, 30167, Germany
| | - Janina Bahnemann
- Institute of Technical Chemistry, Leibniz University Hannover, Callinstraße 5, Hannover, 30167, Germany
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15
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Sun L, Chen Q, Lu H, Wang J, Zhao J, Li P. Electrodialysis with porous membrane for bioproduct separation: Technology, features, and progress. Food Res Int 2020; 137:109343. [DOI: 10.1016/j.foodres.2020.109343] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 05/15/2020] [Accepted: 05/18/2020] [Indexed: 11/26/2022]
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16
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Nice EC. The separation sciences, the front end to proteomics: An historical perspective. Biomed Chromatogr 2020; 35:e4995. [DOI: 10.1002/bmc.4995] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 09/18/2020] [Accepted: 09/23/2020] [Indexed: 02/06/2023]
Affiliation(s)
- Edouard C. Nice
- Department of Biochemistry and Molecular Biology Monash University Clayton Victoria Australia
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17
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Courtney M, Thompson E, Glawdel T, Ren CL. Counterflow Gradient Focusing in Free-Flow Electrophoresis for Protein Fractionation. Anal Chem 2020; 92:7317-7324. [PMID: 32336087 DOI: 10.1021/acs.analchem.0c01024] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Matthew Courtney
- Department of Mechanical and Mechatronics Engineering, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L3G1, Canada
| | - Ethan Thompson
- Department of Nanotechnology Engineering, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L3G1, Canada
| | - Tomasz Glawdel
- Department of Mechanical and Mechatronics Engineering, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L3G1, Canada
| | - Carolyn L. Ren
- Department of Mechanical and Mechatronics Engineering, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L3G1, Canada
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18
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Jender M, Novo P, Maehler D, Münchberg U, Janasek D, Freier E. Multiplexed Online Monitoring of Microfluidic Free-Flow Electrophoresis via Mass Spectrometry. Anal Chem 2020; 92:6764-6769. [PMID: 32289220 DOI: 10.1021/acs.analchem.0c00996] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Free-flow electrophoresis is a tool for the continuous fractionation of electrically charged analytes. In this study, we introduce a novel method to couple microchip-based free-flow electrophoresis with mass spectrometry. The successive connection of multiple microchip outlets to the electrospray ionization source of a mass spectrometer is automated using a multiposition valve. With this novel setup, it is possible to continuously fractionate and collect compounds while simultaneously monitoring the process online with mass spectrometry. The functionality of the method is demonstrated by the successful separation and identification of the biomolecules AMP, ATP, and CoA, which are fundamental for numerous biochemical processes in every organism.
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Affiliation(s)
- Matthias Jender
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Otto-Hahn-Str. 6b, 44227 Dortmund, Germany
| | - Pedro Novo
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Otto-Hahn-Str. 6b, 44227 Dortmund, Germany
| | - Dominic Maehler
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Otto-Hahn-Str. 6b, 44227 Dortmund, Germany
| | - Ute Münchberg
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Otto-Hahn-Str. 6b, 44227 Dortmund, Germany
| | - Dirk Janasek
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Otto-Hahn-Str. 6b, 44227 Dortmund, Germany
| | - Erik Freier
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Otto-Hahn-Str. 6b, 44227 Dortmund, Germany
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19
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Khnouf R, Han C. Isotachophoresis-Enhanced Immunoassays: Challenges and opportunities. IEEE NANOTECHNOLOGY MAGAZINE 2020. [DOI: 10.1109/mnano.2020.2966028] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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20
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Abstract
Electrokinetic separation techniques in microfluidics are a powerful analytical chemistry tool, although an inherent limitation of microfluidics is their low sample throughput. In this article we report a free-flow variant of an electrokinetic focusing method, namely ion concentration polarization focusing (ICPF). The analytes flow continuously through the system via pressure driven flow while they separate and concentrate perpendicularly to the flow by ICPF. We demonstrate free flow ion concentration polarization focusing (FF-ICPF) in two operating modes, namely peak and plateau modes. Additionally, we showed the separation resolution could be improved by the use of an electrophoretic spacer. We report a concentration factor of 10 in human blood plasma in continuous flow at a flow rate of 15 μL min-1.
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Affiliation(s)
- Vasileios A Papadimitriou
- BIOS Lab on a Chip group, MESA+ Institute for Nanotechnology, Max Planck Centre for Complex Fluid Dynamics and Technical Medical Centre, University of Twente, Enschede 7500 AE, The Netherlands
| | - Loes I Segerink
- BIOS Lab on a Chip group, MESA+ Institute for Nanotechnology, Max Planck Centre for Complex Fluid Dynamics and Technical Medical Centre, University of Twente, Enschede 7500 AE, The Netherlands
| | - Jan C T Eijkel
- BIOS Lab on a Chip group, MESA+ Institute for Nanotechnology, Max Planck Centre for Complex Fluid Dynamics and Technical Medical Centre, University of Twente, Enschede 7500 AE, The Netherlands
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21
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Kinde TF, Hess N, Dutta D. Enhancement in MS-based peptide detection by microfluidic free-flow zone electrophoresis. Electrophoresis 2020; 41:545-553. [PMID: 31985060 DOI: 10.1002/elps.201900321] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 01/08/2020] [Accepted: 01/10/2020] [Indexed: 01/07/2023]
Abstract
Matrix components are known to significantly alter the ionization of a target analyte in ESI-based measurements particularly when working with complex biological samples. This issue however may be alleviated by extracting the analyte of interest from the original sample into a relatively simple matrix compatible with ESI mass-spectrometric analysis. In this article, we report a microfluidic device that enables such extraction of small peptide molecules into an ESI-compatible solvent stream significantly improving both the sensitivity and reproducibility of the measurements. The reported device realizes this analyte extraction capability based on the free-flow zone electrophoretic fractionation process using a set of internal electrodes placed across the width of the analysis channel. Employing lateral electric fields and separation distances of 75 V/cm and 600 µm, respectively, efficient extraction of the model peptide human angiotensin II was demonstrated allowing a reduction in its detection limit by one to three orders of magnitude using the ESI-MS method. The noted result was obtained in our experiments both for a relatively simple specimen comprising DNA strands and angiotensin II as well as for human serum samples spiked with the same model peptide.
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Affiliation(s)
- Tristan F Kinde
- Department of Chemistry, University of Wyoming, Laramie, WY, USA
| | - Natalie Hess
- Department of Chemistry, University of Wyoming, Laramie, WY, USA
| | - Debashis Dutta
- Department of Chemistry, University of Wyoming, Laramie, WY, USA
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22
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Hügle M, Behrmann O, Raum M, Hufert FT, Urban GA, Dame G. A lab-on-a-chip for free-flow electrophoretic preconcentration of viruses and gel electrophoretic DNA extraction. Analyst 2020; 145:2554-2561. [DOI: 10.1039/c9an02333j] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
A lab-on-a-chip for FFE preconcentration of viruses and gel electrophoretic DNA extraction: complete preparation of amplifiable DNA from dilute specimens.
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Affiliation(s)
- Matthias Hügle
- Laboratory for Sensors
- Department of Microsystems Engineering (IMTEK)
- University of Freiburg
- Freiburg
- Germany
| | - Ole Behrmann
- Laboratory for Sensors
- Department of Microsystems Engineering (IMTEK)
- University of Freiburg
- Freiburg
- Germany
| | - Madlen Raum
- Laboratory for Sensors
- Department of Microsystems Engineering (IMTEK)
- University of Freiburg
- Freiburg
- Germany
| | - Frank T. Hufert
- Institute of Microbiology and Virology
- Brandenburg Medical School Theodor Fontane
- Neuruppin
- Germany
| | - Gerald A. Urban
- Laboratory for Sensors
- Department of Microsystems Engineering (IMTEK)
- University of Freiburg
- Freiburg
- Germany
| | - Gregory Dame
- Institute of Microbiology and Virology
- Brandenburg Medical School Theodor Fontane
- Neuruppin
- Germany
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23
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Ashrafizadeh SN, Seifollahi Z, Ganjizade A, Sadeghi A. Electrophoresis of spherical soft particles in electrolyte solutions: A review. Electrophoresis 2019; 41:81-103. [DOI: 10.1002/elps.201900236] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 11/11/2019] [Accepted: 11/11/2019] [Indexed: 02/01/2023]
Affiliation(s)
- Seyed Nezameddin Ashrafizadeh
- Research Lab for Advanced Separation ProcessesDepartment of Chemical EngineeringIran University of Science and Technology Tehran Iran
| | - Zahra Seifollahi
- Research Lab for Advanced Separation ProcessesDepartment of Chemical EngineeringIran University of Science and Technology Tehran Iran
| | - Ardalan Ganjizade
- Research Lab for Advanced Separation ProcessesDepartment of Chemical EngineeringIran University of Science and Technology Tehran Iran
| | - Arman Sadeghi
- Department of Mechanical EngineeringUniversity of Kurdistan Sanandaj Iran
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24
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Stastna M. Continuous flow electrophoretic separation - Recent developments and applications to biological sample analysis. Electrophoresis 2019; 41:36-55. [PMID: 31650578 DOI: 10.1002/elps.201900288] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 10/08/2019] [Accepted: 10/10/2019] [Indexed: 01/23/2023]
Abstract
Continuous flow electrophoretic separation with continuous sample loading provides the advantage of processing volumes of any sizes, as well as the benefit of a real-time monitoring and optimization of the separation process. In addition, the spatial separation of the sample enables collecting multiple separated components simultaneously and in a continuous manner. The separation is usually performed in mild buffers without organic solvents and detergents (sample biological activity is retained) and it is carried out without usage of a solid support in the separation space preventing the interaction of the sample with it (high sample recovery). The method is used for the separation of proteins/peptides in proteomic applications, and its great applicability is to the separation of the cells, cellular organelles, vesicles, membrane fragments, and DNA. This review focuses on the electrophoretic separation performed in a continuous flow and it describes various electrophoretic modes and instrumental setups. Recent developments in methodology and instrumentation, the integration with other techniques, and the application to the biological sample analysis are discussed as well.
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Affiliation(s)
- Miroslava Stastna
- Institute of Analytical Chemistry of the Czech Academy of Sciences, Brno, Czech Republic
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25
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Dutta D. Stream broadening due to fluid shear across the wider transverse dimension of a free-flow zone electrophoresis channel. PHYSICS OF FLUIDS (WOODBURY, N.Y. : 1994) 2019; 31:073605. [PMID: 31371910 PMCID: PMC6656573 DOI: 10.1063/1.5098460] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 07/02/2019] [Indexed: 05/06/2023]
Abstract
While the pressure-gradient applied along the length of a free-flow zone electrophoresis (FFZE) chamber is known to produce a parabolic flow profile for the carrier electrolyte across the narrower channel dimension (typically the channel depth), additional fluid shear can arise across the channel width due to a variety of reasons. Most commonly, any variation in the pressure-drop or channel depth across this wider dimension can lead to a gradient in the liquid flow velocity along it, significantly altering the stream broadening and, thereby, the separation performance of the assay. This article assesses the effect of such fluid shear on stream broadening during the FFZE process by describing a mathematical framework for solving the relevant advection-diffusion equation based on the method-of-moments approach. A closed-form expression for the leading order term describing the additional contribution to the spatial stream variance has been derived considering a small linear gradient in the liquid velocity across the wider transverse dimension of the FFZE chamber. The noted analysis predicts this contribution to be governed by two Péclet numbers that are evaluated based on the axial pressure-driven flow and transverse electrophoretic solute velocities. More importantly, this contribution is shown to vary quadratically with the axial distance traversed by the analyte stream as opposed to the classical linear variation known for all other stream broadening contributions in FFZE systems. The results from the analytic theory have been validated with Monte Carlo simulations, which also establish a time and length scale over which the noted analytical results are applicable.
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26
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DEP-on-a-Chip: Dielectrophoresis Applied to Microfluidic Platforms. MICROMACHINES 2019; 10:mi10060423. [PMID: 31238556 PMCID: PMC6630590 DOI: 10.3390/mi10060423] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 06/15/2019] [Accepted: 06/19/2019] [Indexed: 01/09/2023]
Abstract
Dielectric particles in a non-uniform electric field are subject to a force caused by a phenomenon called dielectrophoresis (DEP). DEP is a commonly used technique in microfluidics for particle or cell separation. In comparison with other separation methods, DEP has the unique advantage of being label-free, fast, and accurate. It has been widely applied in microfluidics for bio-molecular diagnostics and medical and polymer research. This review introduces the basic theory of DEP, its advantages compared with other separation methods, and its applications in recent years, in particular, focusing on the different electrode types integrated into microfluidic chips, fabrication techniques, and operation principles.
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27
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Wang S, Zhang L, Sun H, Chu Z, Chen H, Zhao Y, Zhang W. Carrier ampholyte-free free-flow isoelectric focusing for separation of protein. Electrophoresis 2019; 40:2610-2617. [PMID: 30977523 DOI: 10.1002/elps.201900148] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2019] [Accepted: 04/06/2019] [Indexed: 01/20/2023]
Abstract
Free-flow isoelectric focusing (FFIEF) has the merits of mild separation conditions, high recovery and resolution, but suffers from the issues of ampholytes interference and high cost due to expensive carrier ampholytes. In this paper, a home-made carrier ampholyte-free FFIEF system was constructed via orientated migration of H+ and OH- provided by electrode solutions. When applying an electric field, a linear pH gradient from pH 4 to 9 (R2 = 0.994) was automatically formed by the electromigration of protons and hydroxyl ions in the separation chamber. The carrier ampholyte-free FFIEF system not only avoids interference of ampholyte to detection but also guarantees high separation resolution by establishing stable pH gradient. The separation selectivity was conveniently adjusted by controlling operating voltage and optimizing the composition, concentration and flow rate of the carrier buffer. The constructed system was applied to separation of proteins in egg white, followed by MADLI-TOF-MS identification. Three major proteins, ovomucoid, ovalbumin and ovotransferrin, were successfully separated according to their pI values with 15 mmol/L Tris-acetic acid (pH = 6.5) as carrier buffer at a flow rate of 12.9 mL/min.
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Affiliation(s)
- Shuai Wang
- Shanghai Key Laboratory of Functional Materials Chemistry, East China University of Science and Technology, Shanghai, P. R. China
| | - Lingyi Zhang
- Shanghai Key Laboratory of Functional Materials Chemistry, East China University of Science and Technology, Shanghai, P. R. China
| | - Haofan Sun
- Shanghai Key Laboratory of Functional Materials Chemistry, East China University of Science and Technology, Shanghai, P. R. China
| | - Zhanying Chu
- Shanghai Key Laboratory of Functional Materials Chemistry, East China University of Science and Technology, Shanghai, P. R. China
| | - Haihong Chen
- Shanghai Key Laboratory of Functional Materials Chemistry, East China University of Science and Technology, Shanghai, P. R. China
| | - Yameng Zhao
- Shanghai Key Laboratory of Functional Materials Chemistry, East China University of Science and Technology, Shanghai, P. R. China
| | - Weibing Zhang
- Shanghai Key Laboratory of Functional Materials Chemistry, East China University of Science and Technology, Shanghai, P. R. China
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28
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Gajos R, Polak B, Dzido TH. Some theoretical considerations on preparative separation with orthogonal pressurised planar electrochromatography. J Sep Sci 2019; 42:933-946. [PMID: 30600585 DOI: 10.1002/jssc.201800720] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 12/06/2018] [Accepted: 12/11/2018] [Indexed: 11/09/2022]
Abstract
In this work, separation of multicomponent mixtures containing components with the same and different electrophoretic mobility by using orthogonal pressurised planar electrochromatography is studied theoretically. Additionally, a simple way for determination of a maximum amount of mixture causing volume overload of flat/planar columns used in this technique is presented. In the next stage, effects of change in different parameters on process performance by simulation case studies are investigated. A comparative study of separation productivity of orthogonal pressurised planar electrochromatography with the continuous and periodic modes of mixture delivery and column chromatography is carried out.
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Affiliation(s)
- Rafał Gajos
- Department of Physical Chemistry, Chair of Chemistry, Medical University of Lublin, Lublin, Poland
| | - Beata Polak
- Department of Physical Chemistry, Chair of Chemistry, Medical University of Lublin, Lublin, Poland
| | - Tadeusz H Dzido
- Department of Physical Chemistry, Chair of Chemistry, Medical University of Lublin, Lublin, Poland
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29
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Saar KL, Peter Q, Müller T, Challa PK, Herling TW, Knowles TPJ. Rapid two-dimensional characterisation of proteins in solution. MICROSYSTEMS & NANOENGINEERING 2019; 5:33. [PMID: 31636924 PMCID: PMC6799820 DOI: 10.1038/s41378-019-0072-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 02/25/2019] [Accepted: 03/21/2019] [Indexed: 05/20/2023]
Abstract
Microfluidic platforms provide an excellent basis for working with heterogeneous samples and separating biomolecular components at high throughput, with high recovery rates and by using only very small sample volumes. To date, several micron scale platforms with preparative capabilities have been demonstrated. Here we describe and demonstrate a microfluidic device that brings preparative and analytical operations together onto a single chip and thereby allows the acquisition of multidimensional information. We achieve this objective by using a free-flow electrophoretic separation approach that directs fractions of sample into an on-chip analysis unit, where the fractions are characterised through a microfluidic diffusional sizing process. This combined approach therefore allows simultaneously quantifying the sizes and the charges of components in heterogenous mixtures. We illustrate the power of the platform by describing the size distribution of a mixture comprising components which are close in size and cannot be identified as individual components using state-of-the-art solution sizing techniques on their own. Furthermore, we show that the platform can be used for two-dimensional fingerprinting of heterogeneous protein mixtures within tens of seconds, opening up a possibility to obtain multiparameter data on biomolecular systems on a minute timescale.
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Affiliation(s)
- Kadi L. Saar
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW UK
| | - Quentin Peter
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW UK
- Cavendish Laboratory, Department of Physics, University of Cambridge, J J Thomson Ave, Cambridge, CB3 0HE UK
| | | | - Pavan K. Challa
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW UK
- Cavendish Laboratory, Department of Physics, University of Cambridge, J J Thomson Ave, Cambridge, CB3 0HE UK
| | - Therese W. Herling
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW UK
| | - Tuomas P. J. Knowles
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW UK
- Cavendish Laboratory, Department of Physics, University of Cambridge, J J Thomson Ave, Cambridge, CB3 0HE UK
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30
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Flow rate independent gradient generator and application in microfluidic free-flow electrophoresis. Anal Chim Acta 2018; 1044:77-85. [DOI: 10.1016/j.aca.2018.04.066] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 04/19/2018] [Accepted: 04/26/2018] [Indexed: 11/19/2022]
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31
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Nagl S. Microfluidic Free-Flow Isoelectric Focusing with Real-Time pI Determination. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2018; 1906:113-124. [PMID: 30488389 DOI: 10.1007/978-1-4939-8964-5_8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Free-flow electrophoresis (FFE) may be used for continuous and preparative separation of a wide variety of biomolecules. Isoelectric focusing (IEF) provides for the separation of compounds according to their isoelectric point (pI). Here we describe a microfluidic chip-based protocol for the fabrication, application, and optical monitoring of free-flow isoelectric focusing (FFIEF) of proteins and peptides on the microscale with optical surveillance of the microscopic pH gradient provided by an integrated pH sensing layer. This protocol may be used with modifications also for the FFIEF of other biomolecules and may serve as template for the fabrication of microfluidic chips with integrated fluorescent or luminescent pH sensor layers for FFE and other applications.
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Affiliation(s)
- Stefan Nagl
- Department of Chemistry, The Hong Kong University of Science and Technology, Kowloon, Hong Kong SAR, China.
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32
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Arter WE, Charmet J, Kong J, Saar KL, Herling TW, Müller T, Keyser UF, Knowles TPJ. Combining Affinity Selection and Specific Ion Mobility for Microchip Protein Sensing. Anal Chem 2018; 90:10302-10310. [PMID: 30070105 DOI: 10.1021/acs.analchem.8b02051] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The sensitive detection of proteins is a key objective in many areas of biomolecular science, ranging from biophysics to diagnostics. However, sensing in complex biological fluids is hindered by nonspecific interactions with off-target species. Here, we describe and demonstrate an assay that utilizes both the chemical and physical properties of the target species to achieve high selectivity in a manner not possible by chemical complementarity alone, in complex media. We achieve this objective through a combinatorial strategy, by simultaneously exploiting free-flow electrophoresis for target selection, on the basis of electrophoretic mobility, and conventional affinity-based selection. In addition, we demonstrate amplification of the resultant signal by a catalytic DNA nanocircuit. This approach brings together the inherent solution-phase advantages of microfluidic sample handling with isothermal, enzyme-free signal amplification. With this method, no surface immobilization or washing steps are required, and our assay is well suited to monoepitopic targets, presenting advantages over conventional ELISA techniques.
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Affiliation(s)
- William E Arter
- Cavendish Laboratory , University of Cambridge , JJ Thomson Avenue , Cambridge CB3 0HE , U.K.,Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge CB2 1EW , U.K
| | - Jérôme Charmet
- Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge CB2 1EW , U.K.,Institute of Digital Healthcare, International Digital Laboratory, WMG , University of Warwick , Coventry CV4 7AL , U.K
| | - Jinglin Kong
- Cavendish Laboratory , University of Cambridge , JJ Thomson Avenue , Cambridge CB3 0HE , U.K
| | - Kadi L Saar
- Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge CB2 1EW , U.K
| | - Therese W Herling
- Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge CB2 1EW , U.K
| | | | - Ulrich F Keyser
- Cavendish Laboratory , University of Cambridge , JJ Thomson Avenue , Cambridge CB3 0HE , U.K
| | - Tuomas P J Knowles
- Cavendish Laboratory , University of Cambridge , JJ Thomson Avenue , Cambridge CB3 0HE , U.K.,Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge CB2 1EW , U.K
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33
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Saar KL, Müller T, Charmet J, Challa PK, Knowles TPJ. Enhancing the Resolution of Micro Free Flow Electrophoresis through Spatially Controlled Sample Injection. Anal Chem 2018; 90:8998-9005. [PMID: 29938505 DOI: 10.1021/acs.analchem.8b01205] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Free flow electrophoresis is a versatile technique for the continuous separation of mixtures with both preparative and analytical applications. Microscale versions of free flow electrophoresis are particularly attractive strategies because of their fast separation times, ability to work with small sample volumes, and large surface area to volume ratios facilitating rapid heat transfer, thus minimizing the detrimental effects of Joule heating even at high voltages. The resolution of microscale free flow electrophoresis, however, is limited by the broadening of the analyte beam in the microfluidic channel, an effect that becomes especially pronounced when the analyte is deflected significantly away from its original position. Here, we describe and demonstrate how restricting spatially the sample injection and collection to the regions where the gradients in the velocity distribution of the carrier medium are the smallest allows this broadening effect to be substantially suppressed and hence the resolution of microscale free flow electrophoresis devices to be increased. To demonstrate this concept, we fabricated microfluidic free flow electrophoresis devices with spatially restricted injection nozzles implemented through the use of multilayer soft-photolithography and further integrated quartz based observation areas for fluorescent detection and imaging. With these devices, we demonstrated a 5-fold reduction in the extent of beam broadening relative to conventional free flow electrophoresis approaches with nonrestricted sample introduction. The manifold enhancement in the achievable resolution of microscale free flow electrophoresis devices opens up the possibility of rapid separation and analysis of complex mixtures.
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Affiliation(s)
- Kadi L Saar
- Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge CB2 1EW , United Kingdom
| | - Thomas Müller
- Fluidic Analytics Limited , Unit 5 Chesterton Mill, French's Road , Cambridge CB4 3NP , United Kingdom
| | - Jérôme Charmet
- Institute of Digital Healthcare, WMG , University of Warwick , Coventry CV4 7AL , United Kingdom
| | - Pavan Kumar Challa
- Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge CB2 1EW , United Kingdom
| | - Tuomas P J Knowles
- Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge CB2 1EW , United Kingdom.,Cavendish Laboratory, Department of Physics , University of Cambridge , J J Thomson Avenue , Cambridge CB3 0HE , United Kingdom
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34
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Charmet J, Arosio P, Knowles TP. Microfluidics for Protein Biophysics. J Mol Biol 2018; 430:565-580. [DOI: 10.1016/j.jmb.2017.12.015] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 12/19/2017] [Accepted: 12/20/2017] [Indexed: 01/09/2023]
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35
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Abstract
Micro free-flow electrophoresis (μFFE) is a continuous separation technique in which analytes are streamed through a perpendicularly applied electric field in a planar separation channel. Analyte streams are deflected laterally based on their electrophoretic mobilities as they flow through the separation channel. A number of μFFE separation modes have been demonstrated, including free zone (FZ), micellar electrokinetic chromatography (MEKC), isoelectric focusing (IEF) and isotachophoresis (ITP). Approximately 60 articles have been published since the first μFFE device was fabricated in 1994. We anticipate that recent advances in device design, detection, and fabrication, will allow μFFE to be applied to a much wider range of applications. Applications particularly well suited for μFFE analysis include continuous, real time monitoring and microscale purifications.
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Affiliation(s)
- Alexander C Johnson
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, MN 55455, USA.
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36
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Saar KL, Zhang Y, Müller T, Kumar CP, Devenish S, Lynn A, Łapińska U, Yang X, Linse S, Knowles TPJ. On-chip label-free protein analysis with downstream electrodes for direct removal of electrolysis products. LAB ON A CHIP 2017; 18:162-170. [PMID: 29192926 DOI: 10.1039/c7lc00797c] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The ability to apply highly controlled electric fields within microfluidic devices is valuable as a basis for preparative and analytical processes. A challenge encountered in the context of such approaches in conductive media, including aqueous buffers, is the generation of electrolysis products at the electrode/liquid interface which can lead to contamination, perturb fluid flows and generally interfere with the measurement process. Here, we address this challenge by designing a single layer microfluidic device architecture where the electric potential is applied outside and downstream of the microfluidic device while the field is propagated back to the chip via the use of a co-flowing highly conductive electrolyte solution that forms a stable interface at the separation region of the device. The co-flowing electrolyte ensures that all the generated electrolysis products, including Joule heat and gaseous products, are flowed away from the chip without coming into contact with the analytes while the single layer fabrication process where all the structures are defined lithographically allows producing the devices in a simple yet highly reproducible manner. We demonstrate that by allowing stable and effective application of electric fields in excess of 100 V cm-1, the described platform provides the basis for rapid separation of heterogeneous mixtures of proteins and protein complexes directly in their native buffers as well as for the simultaneous quantification of their charge states. We illustrate this by probing the interactions in a mixture of an amyloid forming protein, amyloid-β, and a molecular chaperone, Brichos, known to inhibit the process of amyloid formation. The availability of a platform for applying stable electric fields and its compatibility with single-layer soft-lithography processes opens up the possibility of separating and analysing a wide range of molecules on chip, including those with similar electrophoretic mobilities.
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Affiliation(s)
- Kadi L Saar
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
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37
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Tharkeshwar AK, Gevaert K, Annaert W. Organellar Omics-A Reviving Strategy to Untangle the Biomolecular Complexity of the Cell. Proteomics 2017; 18:e1700113. [PMID: 29125683 DOI: 10.1002/pmic.201700113] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2017] [Revised: 10/23/2017] [Indexed: 12/18/2022]
Abstract
A eukaryotic cell encompasses many membrane-enclosed organelles, each of these holding several types of biomolecules that exhibit tremendous diversity in terms of their localization and expression. Despite the development of increasingly sensitive analytical tools, the enormous biomolecular complexity that exists within a cell cannot yet be fully resolved as low abundant molecules often remain unrecognized. Moreover, a drawback of whole cell analysis is that it does not provide spatial information and therefore it is not capable of assigning distinct biomolecules to specific compartments or analyzing changes in the composition of these compartments. Reduction of the biomolecular complexity of a sample helps to identify low abundant molecules, but such a reductionist approach requires methods that enable proper isolation and purification of individual cellular organelles. Decades of research have led to the development of a plethora of isolation methods for a broad range of subcellular organelles; yet, in particular, intrinsically dynamic compartments belonging to the endocytic machinery, including the plasma membrane, remain difficult to isolate in a sufficiently pure fraction. In this review, we discuss various methods that are commonly used to isolate subcellular organelles from cells and evaluate their advantages and disadvantages.
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Affiliation(s)
- Arun Kumar Tharkeshwar
- Laboratory for Membrane Trafficking, VIB-Center for Brain and Disease Research, Leuven, Belgium.,Laboratory for Membrane Trafficking, Department of Neurosciences, KU Leuven, Leuven, Belgium.,Department of Cell Biology, Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, CT, USA
| | - Kris Gevaert
- VIB-UGent Center for Medical Biotechnology, Ghent, Belgium.,Department of Biochemistry, Ghent University, Belgium
| | - Wim Annaert
- Laboratory for Membrane Trafficking, VIB-Center for Brain and Disease Research, Leuven, Belgium.,Laboratory for Membrane Trafficking, Department of Neurosciences, KU Leuven, Leuven, Belgium
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38
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Zitzmann FD, Jahnke HG, Pfeiffer SA, Frank R, Nitschke F, Mauritz L, Abel B, Belder D, Robitzki AA. Microfluidic Free-Flow Electrophoresis Based Solvent Exchanger for Continuously Operating Lab-on-Chip Applications. Anal Chem 2017; 89:13550-13558. [DOI: 10.1021/acs.analchem.7b03959] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Franziska D. Zitzmann
- Center
for Biotechnology and Biomedicine, Molecular Biological-Biochemical
Processing Technology, Leipzig University, Deutscher Platz 5, D-04103 Leipzig, Germany
| | - Heinz-Georg Jahnke
- Center
for Biotechnology and Biomedicine, Molecular Biological-Biochemical
Processing Technology, Leipzig University, Deutscher Platz 5, D-04103 Leipzig, Germany
| | - Simon A. Pfeiffer
- Institute
of Analytical Chemistry, Leipzig University, Linnéstraße 3, 04103 Leipzig, Germany
| | - Ronny Frank
- Center
for Biotechnology and Biomedicine, Molecular Biological-Biochemical
Processing Technology, Leipzig University, Deutscher Platz 5, D-04103 Leipzig, Germany
| | - Felix Nitschke
- Center
for Biotechnology and Biomedicine, Molecular Biological-Biochemical
Processing Technology, Leipzig University, Deutscher Platz 5, D-04103 Leipzig, Germany
| | - Laura Mauritz
- Institute
of Analytical Chemistry, Leipzig University, Linnéstraße 3, 04103 Leipzig, Germany
| | - Bernd Abel
- Leibniz Institute
of Surface Engineering (IOM), Permoserstrasse
15, 04318 Leipzig, Germany
| | - Detlev Belder
- Institute
of Analytical Chemistry, Leipzig University, Linnéstraße 3, 04103 Leipzig, Germany
| | - Andrea A. Robitzki
- Center
for Biotechnology and Biomedicine, Molecular Biological-Biochemical
Processing Technology, Leipzig University, Deutscher Platz 5, D-04103 Leipzig, Germany
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39
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Novo P, Janasek D. Current advances and challenges in microfluidic free-flow electrophoresis-A critical review. Anal Chim Acta 2017; 991:9-29. [PMID: 29031303 DOI: 10.1016/j.aca.2017.08.017] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 08/10/2017] [Accepted: 08/11/2017] [Indexed: 12/30/2022]
Abstract
The research field on microfluidic free-flow electrophoresis has developed vast amounts of devices, methods, applications and raised new questions, often in analogy to conventional techniques from which it derives. Most efforts have been employed on device development and a myriad of architectures and fabrication techniques have been reported using simple proof-of-principle separations. As technological aspects reach a quite mature state, researchers' new challenges include the development of protocols for the separation of complex mixtures, as required in the fields of application. The success of this effort is extremely dependent on the capability to transfer the device's fabrication to an industrial setting as well as to ensure interfacing simplicity, namely at the solutions' supply and collection, and actuation such as electric potential application and temperature control. Other advanced applications such as direct interfacing to downstream systems such as mass spectrometry, integration of sensing and feedback controls will require further development in the laboratory. In this review we provide an overview on the field, from basic concepts, through advanced developments both in the theoretical and experimental arenas, and addressing the above details. A comprehensive survey of designs, materials and applications is presented with particular highlights to most recent developments, namely the integration of electrodes, flow control and hyphenation of microfluidic free-flow electrophoresis with other techniques.
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Affiliation(s)
- Pedro Novo
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., 44227, Otto-Hahn-Str. 6b, Dortmund, Germany
| | - Dirk Janasek
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., 44227, Otto-Hahn-Str. 6b, Dortmund, Germany.
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40
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Nagl S. Micro free-flow isoelectric focusing with integrated optical pH sensors. Eng Life Sci 2017; 18:114-123. [PMID: 32624893 DOI: 10.1002/elsc.201700035] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 02/07/2017] [Accepted: 07/13/2017] [Indexed: 01/12/2023] Open
Abstract
Recently, a new observation method for monitoring of pH gradients in microfluidic free-flow electrophoresis has emerged. It is based on the use of chip-integrated fluorescent or luminescent micro sensor layers. These are able to monitor pH gradients in miniaturized separations in real time and spatially resolved; this is particularly useful in isoelectric focusing. Here these multifunctional microdevices that feature continuous separation, monitoring, and in some instances other functionalities, are reviewed. The employed microfabrication procedures to produce these devices are discussed and the different pH sensor matrices that were integrated and their applications in the separation of different types of biomolecules. The procedures for obtaining spatially resolved information about the separated molecules and the pH at the same time and different detection modalities to achieve this such as deep UV fluorescence as well as time-resolved referenced pH sensing and the integration of a precolumn labeling step into these platforms are also highlighted.
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Affiliation(s)
- Stefan Nagl
- Department of Chemistry The Hong Kong University of Science and Technology Kowloon Hong Kong SAR P. R. China
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41
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Novo P, Dell'Aica M, Jender M, Höving S, Zahedi RP, Janasek D. Integration of polycarbonate membranes in microfluidic free-flow electrophoresis. Analyst 2017; 142:4228-4239. [DOI: 10.1039/c7an01514c] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A general difficulty in the miniaturization of free-flow electrophoresis relates to the need to separate electrodes and separation bed compartments.
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Affiliation(s)
- Pedro Novo
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V
- 44227 Dortmund
- Germany
| | - Margherita Dell'Aica
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V
- 44227 Dortmund
- Germany
| | - Matthias Jender
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V
- 44227 Dortmund
- Germany
| | - Stefan Höving
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V
- 44227 Dortmund
- Germany
| | - René P. Zahedi
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V
- 44227 Dortmund
- Germany
| | - Dirk Janasek
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V
- 44227 Dortmund
- Germany
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42
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Li CM, Miao Y, Lingeman RG, Hickey RJ, Malkas LH. Partial Purification of a Megadalton DNA Replication Complex by Free Flow Electrophoresis. PLoS One 2016; 11:e0169259. [PMID: 28036377 PMCID: PMC5201288 DOI: 10.1371/journal.pone.0169259] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Accepted: 12/12/2016] [Indexed: 02/03/2023] Open
Abstract
We describe a gentle and rapid method to purify the intact multiprotein DNA replication complex using free flow electrophoresis (FFE). In particular, we applied FFE to purify the human cell DNA synthesome, which is a multiprotein complex that is fully competent to carry-out all phases of the DNA replication process in vitro using a plasmid containing the simian virus 40 (SV40) origin of DNA replication and the viral large tumor antigen (T-antigen) protein. The isolated native DNA synthesome can be of use in studying the mechanism by which mammalian DNA replication is carried-out and how anti-cancer drugs disrupt the DNA replication or repair process. Partially purified extracts from HeLa cells were fractionated in a native, liquid based separation by FFE. Dot blot analysis showed co-elution of many proteins identified as part of the DNA synthesome, including proliferating cell nuclear antigen (PCNA), DNA topoisomerase I (topo I), DNA polymerase δ (Pol δ), DNA polymerase ɛ (Pol ɛ), replication protein A (RPA) and replication factor C (RFC). Previously identified DNA synthesome proteins co-eluted with T-antigen dependent and SV40 origin-specific DNA polymerase activity at the same FFE fractions. Native gels show a multiprotein PCNA containing complex migrating with an apparent relative mobility in the megadalton range. When PCNA containing bands were excised from the native gel, mass spectrometric sequencing analysis identified 23 known DNA synthesome associated proteins or protein subunits.
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Affiliation(s)
- Caroline M. Li
- Department of Molecular and Cellular Biology, Beckman Research Institute at City of Hope, Duarte, California, United States of America
- * E-mail:
| | - Yunan Miao
- Department of Molecular Medicine, Beckman Research Institute at City of Hope, Duarte, California, United States of America
| | - Robert G. Lingeman
- Department of Molecular and Cellular Biology, Beckman Research Institute at City of Hope, Duarte, California, United States of America
| | - Robert J. Hickey
- Department of Molecular Medicine, Beckman Research Institute at City of Hope, Duarte, California, United States of America
| | - Linda H. Malkas
- Department of Molecular and Cellular Biology, Beckman Research Institute at City of Hope, Duarte, California, United States of America
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43
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Pisenti N, Restelli A, Reschovsky B, Barker D, Campbell G. An ultra-low noise, high-voltage piezo-driver. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:124702. [PMID: 28040942 PMCID: PMC6534351 DOI: 10.1063/1.4969059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We present an ultra-low noise, high-voltage driver suited for use with piezoelectric actuators and other low-current applications. The architecture uses a flyback switching regulator to generate up to 250 V in our current design, with an output of 1 kV or more possible with small modifications. A high slew-rate op-amp suppresses the residual switching noise, yielding a total root-mean-square noise of ≈100 μV (1 Hz-100 kHz). A low-voltage (±10 V), high bandwidth signal can be summed with unity gain directly onto the output, making the driver well-suited for closed-loop feedback applications. Digital control enables both repeatable setpoints and sophisticated control logic, and the circuit consumes less than 150 mA at ±15 V.
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Affiliation(s)
- N.C. Pisenti
- Joint Quantum Institute, University of Maryland and National Institute of Standards and Technology College Park, MD 20742, USA
| | - A. Restelli
- Joint Quantum Institute, University of Maryland and National Institute of Standards and Technology College Park, MD 20742, USA
| | - B.J. Reschovsky
- Joint Quantum Institute, University of Maryland and National Institute of Standards and Technology College Park, MD 20742, USA
| | - D.S. Barker
- Joint Quantum Institute, University of Maryland and National Institute of Standards and Technology College Park, MD 20742, USA
| | - G.K. Campbell
- Joint Quantum Institute, University of Maryland and National Institute of Standards and Technology College Park, MD 20742, USA
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44
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Thomas C, Lu X, Todd A, Raval Y, Tzeng T, Song Y, Wang J, Li D, Xuan X. Charge‐based separation of particles and cells with similar sizes via the wall‐induced electrical lift. Electrophoresis 2016; 38:320-326. [DOI: 10.1002/elps.201600284] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 08/03/2016] [Accepted: 08/04/2016] [Indexed: 12/25/2022]
Affiliation(s)
- Cory Thomas
- Department of Mechanical Engineering Clemson University Clemson SC USA
| | - Xinyu Lu
- Department of Mechanical Engineering Clemson University Clemson SC USA
| | - Andrew Todd
- Department of Mechanical Engineering Clemson University Clemson SC USA
| | - Yash Raval
- Department of Biological Sciences Clemson University Clemson SC USA
| | - Tzuen‐Rong Tzeng
- Department of Biological Sciences Clemson University Clemson SC USA
| | - Yongxin Song
- College of Marine Engineering Dalian Maritime University Dalian P.R. China
| | - Junsheng Wang
- College of Information Science and Technology Dalian Maritime University Dalian P.R. China
| | - Dongqing Li
- Department of Mechanical and Mechatronics Engineering University of Waterloo Waterloo ON Canada
| | - Xiangchun Xuan
- Department of Mechanical Engineering Clemson University Clemson SC USA
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45
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Chen Y, Fang Z, Merritt B, Strack D, Xu J, Lee S. Onset of particle trapping and release via acoustic bubbles. LAB ON A CHIP 2016; 16:3024-32. [PMID: 26805706 DOI: 10.1039/c5lc01420d] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Trapping and sorting of micro-sized objects is one important application of lab on a chip devices, with the use of acoustic bubbles emerging as an effective, non-contact method. Acoustically actuated bubbles are known to exert a secondary radiation force (FSR) on micro-particles and stabilize them on the bubble surface, when this radiation force exceeds the external hydrodynamic forces that act to keep the particles in motion. While the theoretical expression of FSR has been derived by Nyborg decades ago, no direct experimental validation of this force has been performed, and the relationship between FSR and the bubble's ability to trap particles in a given lab on a chip device remains largely empirical. In order to quantify the connection between the bubble oscillation and the resultant FSR, we experimentally measure the amplitude of bubble oscillations that give rise to FSR and observe the trapping and release of a single microsphere in the presence of the mean flow at the corresponding acoustic parameters using an acoustofluidic device. By combining well-developed theories that connect bubble oscillations to the acoustic actuation, we derive the expression for the critical input voltage that leads to particle release into the flow, in good agreement with the experiments.
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Affiliation(s)
- Yun Chen
- Department of Mechanical Engineering, Texas A & M University, College Station, TX 77840, USA.
| | - Zecong Fang
- Department of Mechanical Engineering, Washington State University, Vancouver, WA 98686, USA
| | - Brett Merritt
- Department of Mechanical Engineering, Washington State University, Vancouver, WA 98686, USA
| | - Dillon Strack
- Department of Mechanical Engineering, Texas A & M University, College Station, TX 77840, USA.
| | - Jie Xu
- Department of Mechanical and Industrial Engineering, University of Illinois, Chicago, IL 60607, USA.
| | - Sungyon Lee
- Department of Mechanical Engineering, Texas A & M University, College Station, TX 77840, USA.
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46
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Kong FZ, Yang Y, He YC, Zhang Q, Li GQ, Fan LY, Xiao H, Li S, Cao CX. Design of suitable carrier buffer for free-flow zone electrophoresis by charge-to-mass ratio and band broadening analysis. Electrophoresis 2016; 37:2393-400. [DOI: 10.1002/elps.201600040] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 06/05/2016] [Accepted: 06/14/2016] [Indexed: 11/12/2022]
Affiliation(s)
- Fan-zhi Kong
- Laboratory of Analytical Biochemistry and Bio-separation, State Key Laboratory of Microbial Metabolism, School of Life Science and Biotechnology; Shanghai Jiao Tong University; Shanghai P. R. China
| | - Ying Yang
- Laboratory of Analytical Biochemistry and Bio-separation, State Key Laboratory of Microbial Metabolism, School of Life Science and Biotechnology; Shanghai Jiao Tong University; Shanghai P. R. China
- School of Bioscience and Bioengineering; South China University of Technology; Guangzhou P. R. China
| | - Yu-chen He
- Laboratory of Analytical Biochemistry and Bio-separation, State Key Laboratory of Microbial Metabolism, School of Life Science and Biotechnology; Shanghai Jiao Tong University; Shanghai P. R. China
| | - Qiang Zhang
- Laboratory of Analytical Biochemistry and Bio-separation, State Key Laboratory of Microbial Metabolism, School of Life Science and Biotechnology; Shanghai Jiao Tong University; Shanghai P. R. China
| | - Guo-qing Li
- Laboratory of Analytical Biochemistry and Bio-separation, State Key Laboratory of Microbial Metabolism, School of Life Science and Biotechnology; Shanghai Jiao Tong University; Shanghai P. R. China
| | - Liu-yin Fan
- Laboratory of Analytical Biochemistry and Bio-separation, State Key Laboratory of Microbial Metabolism, School of Life Science and Biotechnology; Shanghai Jiao Tong University; Shanghai P. R. China
| | - Hua Xiao
- Laboratory of Analytical Biochemistry and Bio-separation, State Key Laboratory of Microbial Metabolism, School of Life Science and Biotechnology; Shanghai Jiao Tong University; Shanghai P. R. China
| | - Shan Li
- School of Bioscience and Bioengineering; South China University of Technology; Guangzhou P. R. China
| | - Cheng-xi Cao
- Laboratory of Analytical Biochemistry and Bio-separation, State Key Laboratory of Microbial Metabolism, School of Life Science and Biotechnology; Shanghai Jiao Tong University; Shanghai P. R. China
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47
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Abstract
As the future of health care diagnostics moves toward more portable and personalized techniques, there is immense potential to harness the power of electrical signals for biological sensing and diagnostic applications at the point of care. Electrical biochips can be used to both manipulate and sense biological entities, as they can have several inherent advantages, including on-chip sample preparation, label-free detection, reduced cost and complexity, decreased sample volumes, increased portability, and large-scale multiplexing. The advantages of fully integrated electrical biochip platforms are particularly attractive for point-of-care systems. This review summarizes these electrical lab-on-a-chip technologies and highlights opportunities to accelerate the transition from academic publications to commercial success.
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Affiliation(s)
- Bobby Reddy
- Department of Electrical and Computer Engineering,
- Micro and Nanotechnology Laboratory, University of Illinois at Urbana–Champaign, Urbana, Illinois 61801
| | - Eric Salm
- Department of Bioengineering, and
- Micro and Nanotechnology Laboratory, University of Illinois at Urbana–Champaign, Urbana, Illinois 61801
| | - Rashid Bashir
- Department of Electrical and Computer Engineering,
- Department of Bioengineering, and
- Micro and Nanotechnology Laboratory, University of Illinois at Urbana–Champaign, Urbana, Illinois 61801
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48
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Yang Y, Kong FZ, Liu J, Li JM, Liu XP, Li GQ, Wang JF, Xiao H, Fan LY, Cao CX, Li S. Enhancing resolution of free-flow zone electrophoresis via a simple sheath-flow sample injection. Electrophoresis 2016; 37:1992-7. [DOI: 10.1002/elps.201600002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 04/01/2016] [Accepted: 04/05/2016] [Indexed: 11/10/2022]
Affiliation(s)
- Ying Yang
- School of Bioscience and Bioengineering; South China University of Technology; Guangzhou P. R. China
| | - Fan-Zhi Kong
- Laboratory of Analytical Biochemistry and Bioseparation, State Key Laboratory of Microbial Metabolism, School of Life Science and Biotechnology; Shanghai Jiao Tong University; Shanghai P. R. China
| | - Ji Liu
- School of Bioscience and Bioengineering; South China University of Technology; Guangzhou P. R. China
| | - Jun-Min Li
- School of Bioscience and Bioengineering; South China University of Technology; Guangzhou P. R. China
| | - Xiao-Ping Liu
- Laboratory of Analytical Biochemistry and Bioseparation, State Key Laboratory of Microbial Metabolism, School of Life Science and Biotechnology; Shanghai Jiao Tong University; Shanghai P. R. China
| | - Guo-Qing Li
- Laboratory of Analytical Biochemistry and Bioseparation, State Key Laboratory of Microbial Metabolism, School of Life Science and Biotechnology; Shanghai Jiao Tong University; Shanghai P. R. China
| | - Ju-Fang Wang
- School of Bioscience and Bioengineering; South China University of Technology; Guangzhou P. R. China
| | - Hua Xiao
- Laboratory of Analytical Biochemistry and Bioseparation, State Key Laboratory of Microbial Metabolism, School of Life Science and Biotechnology; Shanghai Jiao Tong University; Shanghai P. R. China
| | - Liu-Yin Fan
- Laboratory of Analytical Biochemistry and Bioseparation, State Key Laboratory of Microbial Metabolism, School of Life Science and Biotechnology; Shanghai Jiao Tong University; Shanghai P. R. China
| | - Cheng-Xi Cao
- Laboratory of Analytical Biochemistry and Bioseparation, State Key Laboratory of Microbial Metabolism, School of Life Science and Biotechnology; Shanghai Jiao Tong University; Shanghai P. R. China
| | - Shan Li
- School of Bioscience and Bioengineering; South China University of Technology; Guangzhou P. R. China
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49
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Hosken BD, Li C, Mullappally B, Co C, Zhang B. Isolation and Characterization of Monoclonal Antibody Charge Variants by Free Flow Isoelectric Focusing. Anal Chem 2016; 88:5662-9. [DOI: 10.1021/acs.analchem.5b03946] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Brian D. Hosken
- Department of Protein Analytical Chemistry, ‡Department of Biological Technologies, Genentech, 1 DNA Way, South San Francisco, California 94080, United States
| | - Charlene Li
- Department of Protein Analytical Chemistry, ‡Department of Biological Technologies, Genentech, 1 DNA Way, South San Francisco, California 94080, United States
| | - Berny Mullappally
- Department of Protein Analytical Chemistry, ‡Department of Biological Technologies, Genentech, 1 DNA Way, South San Francisco, California 94080, United States
| | - Carl Co
- Department of Protein Analytical Chemistry, ‡Department of Biological Technologies, Genentech, 1 DNA Way, South San Francisco, California 94080, United States
| | - Boyan Zhang
- Department of Protein Analytical Chemistry, ‡Department of Biological Technologies, Genentech, 1 DNA Way, South San Francisco, California 94080, United States
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50
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Herzog C, Poehler E, Peretzki AJ, Borisov SM, Aigner D, Mayr T, Nagl S. Continuous on-chip fluorescence labelling, free-flow isoelectric focusing and marker-free isoelectric point determination of proteins and peptides. LAB ON A CHIP 2016; 16:1565-1572. [PMID: 27064144 DOI: 10.1039/c6lc00055j] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We present a microfluidic platform that contains a micro flow reactor for on-chip biomolecule labelling that is directly followed by a separation bed for continuous free-flow electrophoresis and has an integrated hydrogel-based near-infrared fluorescent pH sensor layer. Using this assembly, labelling of protein and peptide mixtures, their separation via free-flow isoelectric focusing and the determination of the isoelectric point (pI) of the separated products via the integrated sensor layer could be carried out within typically around 5 minutes. Spatially-resolved immobilization of fluidic and sensing structures was carried out via multistep photolithography. The assembly was characterized and optimized with respect to their fluidic and pH sensing properties and applied in the IEF of model proteins, peptides and a tryptic digest from physalaemine. We have therefore realized continuous sample preparation and preparative separation, analyte detection, process observation and analyte assignment capability based on pI on a single platform the size of a microscope slide.
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Affiliation(s)
- Christin Herzog
- Institut für Analytische Chemie, Universität Leipzig, Johannisallee 29, 04103 Leipzig, Germany.
| | - Elisabeth Poehler
- Institut für Analytische Chemie, Universität Leipzig, Johannisallee 29, 04103 Leipzig, Germany.
| | - Andrea J Peretzki
- Institut für Analytische Chemie, Universität Leipzig, Johannisallee 29, 04103 Leipzig, Germany.
| | - Sergey M Borisov
- Institut für Analytische Chemie und Lebensmittelchemie, Technische Universität Graz, Stremayrgasse 9/III, 8010 Graz, Austria
| | - Daniel Aigner
- Institut für Analytische Chemie und Lebensmittelchemie, Technische Universität Graz, Stremayrgasse 9/III, 8010 Graz, Austria
| | - Torsten Mayr
- Institut für Analytische Chemie und Lebensmittelchemie, Technische Universität Graz, Stremayrgasse 9/III, 8010 Graz, Austria
| | - Stefan Nagl
- Institut für Analytische Chemie, Universität Leipzig, Johannisallee 29, 04103 Leipzig, Germany.
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