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Yu Z, Cao Y, Tian Y, Ji W, Chen KE, Wang Z, Ren J, Xiao H, Zhang L, Liu W, Fan L, Zhang Q, Cao C. Real-time and quantitative protein detection via polyacrylamide gel electrophoresis and online intrinsic fluorescence imaging. Anal Chim Acta 2024; 1291:342219. [PMID: 38280790 DOI: 10.1016/j.aca.2024.342219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 01/05/2024] [Indexed: 01/29/2024]
Abstract
The detection of intrinsic protein fluorescence is a powerful tool for studying proteins in their native state. Thanks to its label-free and stain-free feature, intrinsic fluorescence detection has been introduced to polyacrylamide gel electrophoresis (PAGE), a fundamental and ubiquitous protein analysis technique, to avoid the tedious detection process. However, the reported methods of intrinsic fluorescence detection were incompatible with online PAGE detection or standard slab gel. Here, we fulfilled online intrinsic fluorescence imaging (IFI) of the standard slab gel to develop a PAGE-IFI method for real-time and quantitative protein detection. To do so, we comprehensively investigated the arrangement of the deep-UV light source to obtain a large imaging area compatible with the standard slab gel, and then designed a semi-open gel electrophoresis apparatus (GEA) to scaffold the gel for the online UV irradiation and IFI with low background noise. Thus, we achieved real-time monitoring of the protein migration, which enabled us to determine the optimal endpoint of PAGE run to improve the sensitivity of IFI. Moreover, online IFI circumvented the broadening of protein bands to enhance the separation resolution. Because of the low background noise and the optimized endpoint, we showcased the quantitative detection of bovine serum albumin (BSA) with a limit of detection (LOD) of 20 ng. The standard slab gel provided a high sample loading volume that allowed us to attain a wide linear range of 0.03-10 μg. These results indicate that the PAGE-IFI method can be a promising alternative to conventional PAGE and can be widely used in molecular biology labs.
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Affiliation(s)
- Zixian Yu
- School of Sensing Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Yiren Cao
- School of Sensing Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China; School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Youli Tian
- School of Life Science and Biotechnology, State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Weicheng Ji
- School of Sensing Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Ke-Er Chen
- School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai, China
| | - Zihao Wang
- School of Sensing Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Jicun Ren
- School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Hua Xiao
- School of Life Science and Biotechnology, State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Lu Zhang
- School of Life Science and Biotechnology, State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Weiwen Liu
- School of Sensing Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Liuyin Fan
- Student Innovation Center, Shanghai Jiao Tong University, Shanghai, 200240, China.
| | - Qiang Zhang
- School of Sensing Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
| | - Chengxi Cao
- School of Sensing Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China; School of Life Science and Biotechnology, State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, 200240, China.
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2
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Schwenzer AK, Kruse L, Jooß K, Neusüß C. Capillary electrophoresis-mass spectrometry for protein analyses under native conditions: Current progress and perspectives. Proteomics 2024; 24:e2300135. [PMID: 37312401 DOI: 10.1002/pmic.202300135] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 05/16/2023] [Accepted: 05/23/2023] [Indexed: 06/15/2023]
Abstract
Native mass spectrometry is a rapidly emerging technique for fast and sensitive structural analysis of protein constructs, maintaining the protein higher order structure. The coupling with electromigration separation techniques under native conditions enables the characterization of proteoforms and highly complex protein mixtures. In this review, we present an overview of current native CE-MS technology. First, the status of native separation conditions is described for capillary zone electrophoresis (CZE), affinity capillary electrophoresis (ACE), and capillary isoelectric focusing (CIEF), as well as their chip-based formats, including essential parameters such as electrolyte composition and capillary coatings. Further, conditions required for native ESI-MS of (large) protein constructs, including instrumental parameters of QTOF and Orbitrap systems, as well as requirements for native CE-MS interfacing are presented. On this basis, methods and applications of the different modes of native CE-MS are summarized and discussed in the context of biological, medical, and biopharmaceutical questions. Finally, key achievements are highlighted and concluded, while remaining challenges are pointed out.
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Affiliation(s)
| | - Lena Kruse
- Department of Chemistry, Aalen University, Aalen, Germany
| | - Kevin Jooß
- Department of Chemistry and Molecular Biosciences, the Chemistry of Life Processes Institute, and the Proteomics Center of Excellence, Northwestern University, Evanston, Illinois, USA
- Division of Bioanalytical Chemistry, Amsterdam Institute of Molecular and Life Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
- Centre for Analytical Sciences Amsterdam (CASA), Amsterdam, The Netherlands
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Groeneveld I, Jaspars A, Akca IB, Somsen GW, Ariese F, van Bommel MR. Use of liquid-core waveguides as photochemical reactors and/or for chemical analysis – An overview. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY 2023. [DOI: 10.1016/j.jpap.2023.100168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
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4
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Groeneveld I, Schoemaker SE, Somsen GW, Ariese F, van Bommel MR. Characterization of a liquid-core waveguide cell for studying the chemistry of light-induced degradation. Analyst 2021; 146:3197-3207. [PMID: 33999083 DOI: 10.1039/d1an00272d] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Many organic compounds undergo changes under the influence of light. This might be beneficial in, for example, water purification, but undesirable when cultural-heritage objects fade or when food ingredients (e.g., vitamins) degrade. It is often challenging to establish a strong link between photodegradation products and their parent molecules due to the complexity of the sample. To allow effective study of light-induced degradation (LID), a low-volume exposure cell was created in which solutes are efficiently illuminated (especially at low concentrations) while simultaneously analysed by absorbance spectroscopy. The new LID cell encompasses a gas-permeable liquid-core waveguide (LCW) connected to a spectrograph allowing collection of spectral data in real-time. The aim of the current study was to evaluate the overall performance of the LID cell by assessing its transmission characteristics, the absolute photon flux achieved in the LCW, and its capacity to study solute degradation in presence of oxygen. The potential of the LID set-up for light-exposure studies was successfully demonstrated by monitoring the degradation of the dyes eosin Y and crystal violet.
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Affiliation(s)
- Iris Groeneveld
- Division of Bioanalytical Chemistry, Amsterdam Institute of Molecular and Life Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands.
| | - Suzan E Schoemaker
- Division of Bioanalytical Chemistry, Amsterdam Institute of Molecular and Life Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands.
| | - Govert W Somsen
- Division of Bioanalytical Chemistry, Amsterdam Institute of Molecular and Life Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands.
| | - Freek Ariese
- LaserLaB, Vrije Universiteit Amsterdam, The Netherlands
| | - Maarten R van Bommel
- Analytical Chemistry Group, van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands and Conservation and Restoration of Cultural Heritage, Amsterdam School for Heritage, Memory and Material Culture, University of Amsterdam, P.O. Box 94552, 1091 GN, Amsterdam, The Netherlands
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5
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Kottke D, Burckhardt BB, Breitkreutz J, Fischer B. Application and validation of a coaxial liquid core waveguide fluorescence detector for the permeation analysis of desmopressin acetate. Talanta 2021; 226:122145. [DOI: 10.1016/j.talanta.2021.122145] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 01/21/2021] [Accepted: 01/22/2021] [Indexed: 01/30/2023]
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6
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Isoelectric focusing array with immobilized pH gradient and dynamic scanning imaging for diabetes diagnosis. Anal Chim Acta 2019; 1063:178-186. [DOI: 10.1016/j.aca.2019.03.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Revised: 03/02/2019] [Accepted: 03/07/2019] [Indexed: 12/24/2022]
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7
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Sydes D, Kler PA, Meyer H, Zipfl P, Lutz D, Huhn C. On-chip intermediate LED-IF-based detection for the control of electromigration in multichannel networks. Anal Bioanal Chem 2016; 408:8713-8725. [DOI: 10.1007/s00216-016-0033-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 10/08/2016] [Accepted: 10/13/2016] [Indexed: 11/30/2022]
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8
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Kraiczek KG, Mannion J, Post S, Tsupryk A, Raghunathan V, Brennen R, Zengerle R. Micromachined Fused Silica Liquid Core Waveguide Capillary Flow Cell. Anal Chem 2015; 88:1100-5. [PMID: 26691325 DOI: 10.1021/acs.analchem.5b03219] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A planar, chip-based flow cell for UV-vis absorbance detection in HPLC is presented. The device features a microfabricated free-standing liquid core waveguide (LCW) capillary detection tube of long path length that is based on total internal reflection. We report on the linearity and calibration slope characteristics of lithographically produced LCWs with different interior/exterior geometries. 3D ray tracing was indispensable in modeling behavior in the more demanding geometries: multipath behavior may be intrinsic to these waveguides with consequent nonlinearity. Fortunately, nonlinearity in lithographically easy-to-produce waveguide geometries (such as with a flat, concave exterior and a round interior) is not as detrimental as might be initially expected. Experimental performance is predictably affected by the attainable surface quality of the LCW and efficient and reproducible coupling of the input light into the LCW.
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Affiliation(s)
- K G Kraiczek
- Agilent Technologies , Hewlett-Packard Strasse 8, D 76337 Waldbronn, Germany.,IMTEK-Department of Microsystems Engineering, University of Freiburg , D-79110 Freiburg, Germany
| | - J Mannion
- Agilent Technologies , 5301 Stevens Creek Boulevard, Santa Clara, California 95051, United States
| | - S Post
- Agilent Technologies , 5301 Stevens Creek Boulevard, Santa Clara, California 95051, United States
| | - A Tsupryk
- Agilent Technologies , 5301 Stevens Creek Boulevard, Santa Clara, California 95051, United States
| | - V Raghunathan
- Agilent Technologies , 5301 Stevens Creek Boulevard, Santa Clara, California 95051, United States
| | - R Brennen
- Agilent Technologies , 5301 Stevens Creek Boulevard, Santa Clara, California 95051, United States
| | - R Zengerle
- IMTEK-Department of Microsystems Engineering, University of Freiburg , D-79110 Freiburg, Germany
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9
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Kler PA, Sydes D, Huhn C. Column–coupling strategies for multidimensional electrophoretic separation techniques. Anal Bioanal Chem 2014; 407:119-38. [DOI: 10.1007/s00216-014-8099-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Revised: 08/06/2014] [Accepted: 08/08/2014] [Indexed: 10/24/2022]
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10
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A visual detection of protein content based on titration of moving reaction boundary electrophoresis. Anal Chim Acta 2013; 774:92-9. [DOI: 10.1016/j.aca.2013.03.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 02/20/2013] [Accepted: 03/03/2013] [Indexed: 11/21/2022]
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11
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Kadjo A, Dasgupta PK. Tutorial: Simulating chromatography with Microsoft Excel Macros. Anal Chim Acta 2013; 773:1-8. [DOI: 10.1016/j.aca.2012.11.055] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Revised: 11/23/2012] [Accepted: 11/25/2012] [Indexed: 10/27/2022]
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12
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de Kort BJ, de Jong GJ, Somsen GW. Native fluorescence detection of biomolecular and pharmaceutical compounds in capillary electrophoresis: Detector designs, performance and applications: A review. Anal Chim Acta 2013; 766:13-33. [DOI: 10.1016/j.aca.2012.12.006] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2012] [Revised: 12/01/2012] [Accepted: 12/03/2012] [Indexed: 01/05/2023]
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13
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Righetti PG, Sebastiano R, Citterio A. Capillary electrophoresis and isoelectric focusing in peptide and protein analysis. Proteomics 2012. [DOI: 10.1002/pmic.201200378] [Citation(s) in RCA: 134] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
| | - Roberto Sebastiano
- Department of Chemistry, Materials and Chemical Engineering “Giulio Natta”; Politecnico di Milano; Milano; Italy
| | - Attilio Citterio
- Department of Chemistry, Materials and Chemical Engineering “Giulio Natta”; Politecnico di Milano; Milano; Italy
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14
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Bytzek AK, Hartinger CG. Capillary electrophoretic methods in the development of metal-based therapeutics and diagnostics: new methodology and applications. Electrophoresis 2012; 33:622-34. [PMID: 22451055 DOI: 10.1002/elps.201100402] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In recent years, capillary electrophoresis (CE) has matured to a standard method in medicinal inorganic chemistry. More and more steps of the drug discovery process are followed by CE. However, not only the number of applications has steadily increased but also the variety of used methodology has significantly broadened and, as compared to a few years ago, a wider scope of separation modes and hyphenated systems has been used. Herein, a summary of the newly utilized CE methods and their applications in metallodrug research in the timeframe 2006-2011 is presented, following related reviews from 2003 and 2007 (Electrophoresis, 2003, 24, 2023-2037; Electrophoresis 2007, 28, 3436-3446). Areas covered include impurity profiling, quality control of pharmaceutical formulations, lipophilicity estimation, interactions between metallodrugs and proteins or nucleotides, and characterization and also quantification of metabolites in biological matrices and real-world samples.
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Affiliation(s)
- Anna K Bytzek
- Institute of Inorganic Chemistry, University of Vienna, Vienna, Austria
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15
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Köhler S, Nagl S, Fritzsche S, Belder D. Label-free real-time imaging in microchip free-flow electrophoresis applying high speed deep UV fluorescence scanning. LAB ON A CHIP 2012; 12:458-463. [PMID: 22011722 DOI: 10.1039/c1lc20558g] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We report on label-free monitoring of microfluidic free-flow electrophoresis (μFFE) separations in real-time using a custom built high speed deep UV laser scanner. In combination with a novel layout realized in fused silica (FS) FFE chips the setup was successfully applied for continuous separations and detection of unlabeled analytes including native proteins by space-resolved intrinsic deep UV fluorescence scanning.
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Affiliation(s)
- Stefan Köhler
- Institute of Analytical Chemistry, University of Leipzig, Linnéstr. 3, 04103 Leipzig, Germany
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Bi X, Yu J, Li L, Jiang H, Huang F, Liu Z. Spatio-temporally resolved detection on a microfluidic chip for monitoring the dynamic processes of molecular events. Analyst 2012; 137:4016-22. [DOI: 10.1039/c2an35650c] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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17
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Membrane-assisted capillary isoelectric focusing coupling with matrix-assisted laser desorption/ionization-Fourier transform mass spectrometry for neuropeptide analysis. J Chromatogr A 2011; 1218:5336-43. [PMID: 21696746 DOI: 10.1016/j.chroma.2011.05.072] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2011] [Revised: 05/13/2011] [Accepted: 05/18/2011] [Indexed: 12/30/2022]
Abstract
Herein we report a highly efficient and reliable membrane-assisted capillary isoelectric focusing (MA-CIEF) system being coupled with MALDI-FTMS for the analysis of complex neuropeptide mixtures. The new interface consists of two membrane-coated joints made near each end of the capillary for applying high voltage, while the capillary ends were placed in the two reservoirs which were filled with anolyte (acid) and catholyte (base) to provide pH difference. Optimizations of CIEF conditions and comparison with conventional CIEF were carried out by using bovine serum albumin (BSA) tryptic peptides. It was shown that the MA-CIEF could provide more efficient, reliable and faster separation with improved sequence coverage when coupled to MALDI-FTMS. Analyses of orcokinin family neuropeptides from crabs Cancer borealis and Callinectes sapidus brain extracts have been conducted using the established MA-CIEF/MALDI-FTMS platform. Increased number of neuropeptides was observed with significantly enhanced MS signal in comparison with direct analysis by MALDI-FTMS. The results highlighted the potential of MA-CIEF as an efficient fractionation tool for coupling to MALDI MS for neuropeptide analysis.
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Kataoka M, Yokoyama H, Henares TG, Kawamura K, Yao T, Hisamoto H. Reagent-release capillary array-isoelectric focusing device as a rapid screening device for IEF condition optimization. LAB ON A CHIP 2010; 10:3341-3347. [PMID: 20714639 DOI: 10.1039/c0lc00019a] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
This report describes the fabrication and characterization of a simple and disposable capillary isoelectric focusing (cIEF) device containing a reagent-release capillary (RRC) array and poly(dimethylsiloxane) (PDMS) platform, which allows rapid (within 10 min) screening of cIEF conditions by introducing a sample solution into plural RRCs by capillary action followed by electric field application. To prepare the RRC, covalent immobilization of poly(dimethylacrylamide) (PDMA) was conducted to suppress electro-osmotic flow (EOF), followed by physical adsorption of the mixture of carrier ampholyte (CA), surfactant, labeling reagent (LR), and other additives to the PDMA surface to construct a two-layer structure inside a square glass capillary. When the sample solution containing proteins was introduced into the RRC, physically adsorbed CA, surfactant, and LR can be dissolved and released into the sample solution. Then, complexation of LR with proteins, mixing with CA and surfactant, and exposure of the PDMA surface spontaneously occurs for the IEF experiments. Here, three different RRCs that immobilize different CAs were prepared, and simultaneous cIEF experiments involving hemoglobin AFSC mixtures for choosing the best CA demonstrated the proof of concept.
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Affiliation(s)
- Masaki Kataoka
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai City, Osaka 599-8531, Japan
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Ramsay LM, Dickerson JA, Dada O, Dovichi NJ. Femtomolar concentration detection limit and zeptomole mass detection limit for protein separation by capillary isoelectric focusing and laser-induced fluorescence detection. Anal Chem 2010; 81:1741-6. [PMID: 19206532 DOI: 10.1021/ac8025948] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Fluorescence tends to produce the lowest detection limits for most forms of capillary electrophoresis. Two issues have discouraged its use in capillary isoelectric focusing. The first issue is fluorescent labeling of proteins. Most labeling reagents react with lysine residues and convert the cationic residue to a neutral or anionic product. At best, these reagents perturb the isoelectric point of the protein. At worse, they convert each protein into hundreds of different fluorescent products that confound analysis. The second issue is the large background signal generated by impurities within commercial ampholytes. This background signal is particularly strong when excited in the blue portion of the spectrum, which is required by many common fluorescent labeling reagents. This paper addresses these issues. For labeling, we employ Chromeo P540, which is a fluorogenic reagent that converts cationic lysine residues to cationic fluorescent products. The reaction products are excited in the green, which reduces the background signal generated by impurities present within the ampholytes. To further reduce the background signal, we photobleach ampholytes with high-power photodiodes. Photobleaching reduced the noise in the ampholyte blank by an order of magnitude. Isoelectric focusing performed with photobleached pH 3-10 ampholytes produced concentration detection limits of 270 +/- 25 fM and mass detection limits of 150 +/- 15 zmol for Chromeo P540 labeled beta-lactoglobulin. Concentration detection limits were 520 +/- 40 fM and mass detection limits were 310 +/- 30 zmol with pH 4-8 ampholytes. A homogenate was prepared from a Barrett's esophagus cell line and separated by capillary isoelectric focusing, reproducibly generating dozens of peaks. The sample taken for the separation was equal to the labeled protein homogenate from three cells.
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Affiliation(s)
- Lauren M Ramsay
- Department of Chemistry, University of Washington, Seattle, Washington 98195, USA
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Lemma T, Pawliszyn J. Human serum albumin interaction with oxaliplatin studied by capillary isoelectric focusing with the whole column imaging detection and spectroscopic method. J Pharm Biomed Anal 2009; 50:570-5. [DOI: 10.1016/j.jpba.2008.10.028] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2008] [Revised: 10/18/2008] [Accepted: 10/20/2008] [Indexed: 11/16/2022]
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21
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Memisevic J, Korampally V, Gangopadhyay S, Grant SA. Characterization of a novel ultra low refractive index material for biosensor application. SENSORS AND ACTUATORS. B, CHEMICAL 2009; 141:227-232. [PMID: 20161155 PMCID: PMC2734105 DOI: 10.1016/j.snb.2009.04.034] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Nanoporous materials can provide significant benefits to the field of biosensors. Their size and porous structure makes them an ideal tool for improving sensor performance. This study characterized a novel ultra low index of refraction nanoporous organosilicate (NPO) material for use as an optical platform for fluorescence-based optical biosensors. While serving as the low index cladding material, the novel coating based on organosilicate nanoparticles also provides an opportunity for a high surface area coating that can be utilized for immobilizing biological probes. Biological molecules were immobilized onto NPO, which was spin-coated on silicon and glass substrates. The biological molecule was composed of Protein A conjugated to AlexaFluor 546 fluorophore and then immobilized onto the NPO substrate via silanization. Sample analysis consisted of spectrofluorometry, FT-IR spectroscopy, scanning electron microscopy, contact angle measurement and ellipsometry. The results showed the presence of emission peaks at 574 nm, indicating that the immobilization of Protein A to the NPO material is possible. When compared to Si and glass substrates not coated with NPO, the results showed a 100X and 10X increase in packing density with the NPO coated films respectively. Ellipsometric analysis, FT-IR, contact angle, and SEM imaging of the surface immobilized NPO films suggested that while the surface modifications did induce some damage, it did not incur significant changes to its unique characteristics, i.e., pore structure, wettability and index of refraction. It was concluded that NPO films would be a viable sensor substrate to enhance sensitivity and improve sensor performance.
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Affiliation(s)
- Jasenka Memisevic
- Department of Biological Engineering, University of Missouri, Columbia, MO 65211, USA
| | - Venumadhav Korampally
- Department of Electrical and Computer Engineering, University of Missouri, Columbia, MO 65211, USA
| | - Shubhra Gangopadhyay
- Department of Electrical and Computer Engineering, University of Missouri, Columbia, MO 65211, USA
| | - Sheila A. Grant
- Department of Biological Engineering, University of Missouri, Columbia, MO 65211, USA
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Ou J, Glawdel T, Ren CL, Pawliszyn J. Fabrication of a hybrid PDMS/SU-8/quartz microfluidic chip for enhancing UV absorption whole-channel imaging detection sensitivity and application for isoelectric focusing of proteins. LAB ON A CHIP 2009; 9:1926-1932. [PMID: 19532968 DOI: 10.1039/b821438g] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A poly(dimethylsiloxane)(PDMS)/SU-8/quartz hybrid chip was developed and applied in the isoelectric focusing (IEF) of proteins with ultraviolet (UV) absorbance-based whole-channel imaging detection (UV-WCID). Each hybrid chip was made of three layers: a PDMS flat top substrate, a bottom quartz substrate and a middle layer of SU-8 photoresist. The SU-8 serves two purposes: it contains the microchannel used for IEF separation, and acts as an optical slit that absorbs UV light below 300 nm improving detection sensitivity in WCID. The novel hybrid design demonstrates a two to three times improvement in sensitivity over a comparable PDMS/PDMS design. In addition, the hybrid chip exhibits increased heat dissipation due to the superior thermal conductivity of the bottom quartz substrate allowing for larger electric fields to be used in separations. The hybrid design with IEF-UV-WCID was successful in resolving a complicated sample, hemoglobin control, with high fidelity.
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Affiliation(s)
- Junjie Ou
- Department of Chemistry, University of Waterloo, Waterloo, Ontario, CanadaN2L 3G1
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23
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Wu XZ, Asai S, Yamaguchi Y. Study of protein-protein binding reaction by whole-column fluorescence-imaged CIEF. Electrophoresis 2009; 30:1552-7. [DOI: 10.1002/elps.200800506] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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24
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Horká M, Horký J, Matoušková H, Šlais K. Free flow and capillary isoelectric focusing of bacteria from the tomatoes plant tissues. J Chromatogr A 2009; 1216:1019-24. [DOI: 10.1016/j.chroma.2008.12.024] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2008] [Revised: 12/08/2008] [Accepted: 12/10/2008] [Indexed: 11/16/2022]
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Liang L, Dou P, Dong M, Ke X, Bian N, Liu Z. Study on a hidden protein-DNA binding in salmon sperm DNA sample by dynamic kinetic capillary isoelectric focusing. Anal Chim Acta 2009; 650:106-10. [PMID: 19720180 DOI: 10.1016/j.aca.2009.01.026] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2008] [Revised: 12/16/2008] [Accepted: 01/13/2009] [Indexed: 10/21/2022]
Abstract
Nuclease P1 is an important enzyme that hydrolyzes RNA or single-stranded DNA into nucleotides, and complete digestion is an essential basis for assays based on this enzyme. To digest a doubled-stranded DNA, the enzyme is usually combined with heat denaturing, which breaks doubled-stranded DNA into single strands. This paper presents an un-expected phenomenon that nuclease P1, in combination with heat denaturing, fails to completely digest a DNA sample extracted from salmon sperm. Under the experimental conditions used, at which nuclease P1 can completely digest calf thymus DNA, the digestion yield of salmon sperm DNA was only 89.5%. Spectrometric measurement indicated that a total protein of 4.7% is present in the DNA sample. To explain the reason for this phenomenon, the dynamic kinetic capillary isoelectric focusing (DK-CIEF) approach proposed previously, which allows for the discrimination of different types of protein-DNA interactions and the measurement of the individual dissociation rate constants, was modified and applied to examine possible protein-DNA interactions involved. It was found that a non-specific DNA-protein binding occurs in the sample, the dissociation rate constant for which was measured to be 7.05+/-0.83x10(-3) s(-1). The formation of DNA-protein complex was suggested to be the main reason for the incomplete digestion of the DNA sample. The modified DK-CIEF approach can be applied as general DNA samples, with the advantages of fast speed and low sample consumption.
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Affiliation(s)
- Liang Liang
- School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
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26
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KITAGAWA F, AIZAWA S, OTSUKA K. High-speed Analysis of Proteins by Microchip Isoelectric Focusing with Linear-imaging UV Detection. ANAL SCI 2009; 25:979-84. [DOI: 10.2116/analsci.25.979] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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27
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Ramsay LM, Dickerson JA, Dovichi NJ. Attomole protein analysis by CIEF with LIF detection. Electrophoresis 2009; 30:297-302. [DOI: 10.1002/elps.200800498] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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28
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Liu Z, Ou J, Samy R, Glawdel T, Huang T, Ren CL, Pawliszyn J. Side-by-side comparison of disposable microchips with commercial capillary cartridges for application in capillary isoelectric focusing with whole column imaging detection. LAB ON A CHIP 2008; 8:1738-1741. [PMID: 18813399 DOI: 10.1039/b807646d] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Simple-structured, well-functioned disposable poly(dimethylsiloxane) (PDMS) microchips were developed for capillary isoelectric focusing with whole column imaging detection (CIEF-WCID). Side-by-side comparison of the developed microchips with well-established commercial capillary cartridges demonstrated that the disposable microchips have comparable performance as well as advantages such as absence of lens effect and possibility of high-aspect-ratio accompanied with a dramatic reduction in cost.
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Affiliation(s)
- Zhen Liu
- School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, China.
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30
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Recent developments in capillary isoelectric focusing. J Chromatogr A 2008; 1204:157-70. [DOI: 10.1016/j.chroma.2008.05.057] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2008] [Revised: 04/30/2008] [Accepted: 05/08/2008] [Indexed: 12/22/2022]
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31
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Ou J, Glawdel T, Samy R, Wang S, Liu Z, Ren CL, Pawliszyn J. Integration of Dialysis Membranes into a Poly(dimethylsiloxane) Microfluidic Chip for Isoelectric Focusing of Proteins Using Whole-Channel Imaging Detection. Anal Chem 2008; 80:7401-7. [DOI: 10.1021/ac8010928] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Junjie Ou
- Department of Mechanical and Mechatronics Engineering and Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1, and School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
| | - Tomasz Glawdel
- Department of Mechanical and Mechatronics Engineering and Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1, and School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
| | - Razim Samy
- Department of Mechanical and Mechatronics Engineering and Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1, and School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
| | - Shuwen Wang
- Department of Mechanical and Mechatronics Engineering and Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1, and School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
| | - Zhen Liu
- Department of Mechanical and Mechatronics Engineering and Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1, and School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
| | - Carolyn L. Ren
- Department of Mechanical and Mechatronics Engineering and Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1, and School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
| | - Janusz Pawliszyn
- Department of Mechanical and Mechatronics Engineering and Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1, and School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
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32
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Investigation of interaction between human hemoglobin A0 and platinum anticancer drugs by capillary isoelectric focusing with whole column imaging detection. J Sep Sci 2008; 31:1803-9. [DOI: 10.1002/jssc.200700418] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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33
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Dou P, Liu Z, He J, Xu JJ, Chen HY. Rapid and high-resolution glycoform profiling of recombinant human erythropoietin by capillary isoelectric focusing with whole column imaging detection. J Chromatogr A 2008; 1190:372-6. [DOI: 10.1016/j.chroma.2008.03.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2008] [Revised: 02/24/2008] [Accepted: 03/03/2008] [Indexed: 01/01/2023]
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34
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Pharmaceutical applications of isoelectric focusing on microchip with imaged UV detection. J Chromatogr A 2008; 1181:145-52. [DOI: 10.1016/j.chroma.2007.12.046] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2007] [Revised: 11/20/2007] [Accepted: 12/18/2007] [Indexed: 11/24/2022]
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35
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Ren K, Liang Q, Yao B, Luo G, Wang L, Gao Y, Wang Y, Qiu Y. Whole column fluorescence imaging on a microchip by using a programmed organic light emitting diode array as a spatial-scanning light source and a single photomultiplier tube as detector. LAB ON A CHIP 2007; 7:1574-1580. [PMID: 17960288 DOI: 10.1039/b707118c] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
A novel miniaturized, integrated whole-column imaging detection (WCID) system on a microchip is presented. In this system, a program controlled organic light emitting diode (OLED) array was used as a spatial-scanning light source, to achieve imaging by the time sequence of the excited fluorescence. By this mechanism, a photomultiplier tube (PMT) instead of a charge coupled detector (CCD) can be applied to the imaging. Unlike conventional systems, no lenses, fibers or any mechanical components are required either. The novel flat light source provides uniform excitation light without size limitations and outputs a stronger power by pulse driving. The scanning mode greatly reduced the power consumption of the light source, which is valuable for a portable system. Meanwhile, this novel simplified system has a broader linear range, higher sensitivity and higher efficiency in data collection. Isoelectric focusing of R-phycoerythrin (PE) and monitoring of the overall process with WCID were performed on this system. The limit of detection (LOD) was 38 ng mL(-1) or 3.2 pg at 85 nL per column injection of PE. The system provides a technique for WCID capillary isoelectric focusing (cIEF) on chip and can be used for throughput analysis.
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Affiliation(s)
- Kangning Ren
- Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing, 100084, China
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36
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Abstract
Liquid-core waveguide (LCW) brings about several advantages in CE. This review discusses some aspects of fundamental and practical importance involved in this method. Sensitivity in absorption and fluorescence detection is in general improved by more than one order of magnitude over usual crossbeam detection arrangements; the improvements come from the long light path in absorption detection and low light scattering in fluorescence detection. Versatile instrumental arrangements are another advantage of LCW in CE, leading to several detection schemes, some of which provide information that is not gained by usual capillary-end crossbeam detection, e.g. whole-capillary imaging, simultaneous monitoring of multicapillary separation, and kinetic evaluation. The high potential and perspectives of LCW in CE are discussed based on the state-of-the-art developments.
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Affiliation(s)
- Tetsuo Okada
- Department of Chemistry, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551, Japan.
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37
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Horká M, Růzicka F, Holá V, Slais K. CE separation of proteins and yeasts dynamically modified by PEG pyrenebutanoate with fluorescence detection. Electrophoresis 2007; 28:2300-7. [PMID: 17557360 DOI: 10.1002/elps.200600710] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The optimized protocols of the bioanalytes separation, proteins and yeasts, dynamically modified by the nonionogenic tenside PEG pyrenebutanoate, were applied in CZE and CIEF with the acidic gradient in pH range 2-5.5, both with fluorescence detection. PEG pyrenebutanoate was used as a buffer additive for a dynamic modification of proteins and/or yeast samples. The narrow peaks of modified analytes were detected. The values of the pI's of the labeled proteins were calculated using new fluorescent pI markers in CIEF and they were found to be comparable with pI's of the native compounds. As an example of the possible use of the suggested CIEF technique, the mixed cultures of yeasts, Candida albicans, Candida glabrata, Candida kefyr, Candida krusei, Candida lusitaniae, Candida parapsilosis, Candida tropicalis, Candida zeylanoides, Geotrichum candidum, Saccharomyces cerevisiae, Trichosporon asahii and Yarrowia lipolytica, were reproducibly focused and separated with high sensitivity. Using UV excitation for the on-column fluorometric detection, the minimum detectable amounts of analytes, femtograms of proteins and down to ten cells injected on the separation capillary, were estimated.
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Affiliation(s)
- Marie Horká
- Institute of Analytical Chemistry, Academy of Sciences of the Czech Republic, Brno, Czech Republic.
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38
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Liu Z, Wu SS, Pawliszyn J. Characterization of plant growth-promoting rhizobacteria using capillary isoelectric focusing with whole column imaging detection. J Chromatogr A 2007; 1140:213-8. [PMID: 17166508 DOI: 10.1016/j.chroma.2006.11.093] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2006] [Revised: 11/27/2006] [Accepted: 11/29/2006] [Indexed: 11/26/2022]
Abstract
Capillary isoelectric focusing (cIEF) can be a useful tool for the characterization and identification of microbes. Based on the whole column imaging detection (WCID) technique and using plant growth-promoting rhizobacteria (PGPR) as test microbes, we present a two-level cIEF characterization method for the characterization and identification of bacteria. Intact bacteria were first characterized according to their apparent isoelectric points measured by cIEF-WCID and then lysed bacteria were further characterized by cIEF profiling of the intracellular proteins. Cellular clustering was found to be the main experimental barrier for the characterization of intact bacteria. The addition of sodium chloride (100mM) to the sample mixture was found to be an effective way to reduce clustering. Due to the high efficiency and high resolution of cIEF-WCID, characterization of bacteria according to their intracellular proteins can be implemented simply and quickly without optimization of the experimental conditions. To improve the detection sensitivity with laser induced fluorescence (LIF)-WCID, the possibility to label bacteria with a non-covalent fluorescent dye, NanoOrange, was explored.
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Affiliation(s)
- Zhen Liu
- Department of Chemistry, Nanjing University, Nanjing 210093, China.
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39
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Monton MRN, Terabe S. Sample enrichment techniques in capillary electrophoresis: Focus on peptides and proteins. J Chromatogr B Analyt Technol Biomed Life Sci 2006; 841:88-95. [PMID: 16716769 DOI: 10.1016/j.jchromb.2006.04.017] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2006] [Revised: 04/17/2006] [Accepted: 04/20/2006] [Indexed: 01/03/2023]
Abstract
Compared to chromatography-based techniques, the concentration limits of detection (CLOD) associated with capillary electrophoresis are worse, and these have largely precluded their use in many practical applications. To overcome this limitation, researchers from various disciplines have exerted tremendous efforts toward developing strategies for increasing the concentration sensitivities of capillary electrophoresis (CE) systems, via the so-called sample enrichment techniques. This review highlights selected developments and advances in this area as applied to the analyses of proteins and peptides in the last 5 years.
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Affiliation(s)
- Maria Rowena N Monton
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata 997-0017, Japan
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40
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Wada A, Harada M, Okada T. Kinetic Monitoring of Electrophoretically Induced Solute Reaction by Axial Absorption Detection with Liquid-Core Waveguide. Anal Chem 2006; 78:4709-12. [PMID: 16808486 DOI: 10.1021/ac060175c] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Teflon AF-2400 capillary has been used for capillary electrophoretic separation as well as for liquid-core waveguide for axial absorption detection. This separation/detection scheme has allowed continuous monitoring of electrophoretically induced reactions. In this paper, the decomposition of Cd2+ complex with 4-(2-pyridylazo)resorcinol has been tested, and its decomposition kinetics has been studied. A simple modeling has predicted the single-exponential decay of the absorbance detected by the present axial absorption detector and has allowed the estimation of the decomposition rate constant for this reaction.
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Affiliation(s)
- Akira Wada
- Department of Chemistry, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551, Japan
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41
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Kasicka V. Recent developments in capillary electrophoresis and capillary electrochromatography of peptides. Electrophoresis 2006; 27:142-75. [PMID: 16307429 DOI: 10.1002/elps.200500527] [Citation(s) in RCA: 133] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The article gives a comprehensive review on the recent developments in the applications of high-performance capillary electromigration methods, zone electrophoresis, isotachophoresis, isoelectric focusing, affinity electrophoresis, electrokinetic chromatography, and electrochromatography, to analysis, preparation, and physicochemical characterization of peptides. The article presents new approaches to the theoretical description and experimental verification of electromigration behavior of peptides, covers the methodological aspects of capillary electroseparations of peptides, such as rational selection of separation conditions, sample preparation, suppression of peptide adsorption, new developments in individual separation modes, and new designs of detection systems. Several types of applications of capillary electromigration methods to peptide analysis are presented: conventional qualitative and quantitative analysis, purity control, determination in biomatrices, monitoring of chemical and enzymatical reactions and physical changes, amino acid and sequence analysis, and peptide mapping of proteins. Some examples of micropreparative peptide separations are given and capabilities of capillary electromigration techniques to provide important physicochemical characteristics of peptides are demonstrated.
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Affiliation(s)
- Václav Kasicka
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
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42
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Abstract
This review article with 304 references describes recent developments in CE of proteins, and covers the two years since the previous review (Hutterer, K., Dolník, V., Electrophoresis 2003, 24, 3998-4012) through Spring 2005. It covers topics related to CE of proteins, including modeling of the electrophoretic migration of proteins, sample pretreatment, wall coatings, improving separation, various forms of detection, special electrophoretic techniques such as affinity CE, CIEF, and applications of CE to the analysis of proteins in real-world samples including human body fluids, food and agricultural samples, protein pharmaceuticals, and recombinant protein preparations.
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43
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Liu Z, Pawliszyn J. Microdialysis hollow fiber as a macromolecule trap for on-line coupling of solid phase microextraction and capillary electrophoresis. Analyst 2006; 131:522-8. [PMID: 16568169 DOI: 10.1039/b511882d] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
On-line coupling of solid phase microextraction (SPME) and capillary electrophoresis (CE) is highly desirable due to the apparent advantages of the two techniques particularly in the context of microanalysis. However, the hyphenation is a significant challenge, because of band broadening and analyte carryover caused by the slow kinetics of analyte desorption in liquid phase. A novel strategy was presented in this study to overcome these problems. Analytes desorbed from an SPME fiber, which was held by an adapter, were first transferred by electrophoretic migration into a short piece of microdialysis hollow fiber, which was located at the inlet of a CE system. Analytes with molecular weights greater than the molecular weight cut-off of the microdialysis material were trapped in the microdialysis hollow fiber due to the dialysis effect. Then, under another electric field with different electrode polarity, the analytes trapped in the microdialysis hollow fiber migrated into the separation capillary and were separated. In the coupling approach, the microdialysis hollow fiber functioned as a macromolecule trap and a sample pre-concentrator as well. Band broadening was eliminated because the initial sample volume was very small (at nL level). Meanwhile, analyte carryover was eliminated because the desorption time could be as long as needed. Coupling of SPME with CE including two modes, capillary zone electrophoresis (CZE) and capillary isoelectric focusing (CIEF), was successfully demonstrated with proteins as test analytes. High efficiency and high resolution were obtained. The detection limits with UV absorbance whole-column imaging detection were 3.0 x 10(-7) and 3.0 x 10(-8) M (S/N = 3) for beta-lactoglobulin A and ovalbumin, respectively.
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Affiliation(s)
- Zhen Liu
- Department of Chemistry, Nanjing University, Nanjing 210093, China
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44
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Huang X, Ren J. On-line chemiluminescence detection for isoelectric focusing of heme proteins on microchips. Electrophoresis 2005; 26:3595-601. [PMID: 16136525 DOI: 10.1002/elps.200500076] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In this paper we present a sensitive chemiluminescence (CL) detection of heme proteins coupled with microchip IEF. The detection principle was based on the catalytic effects of the heme proteins on the CL reaction of luminol-H2O2 enhanced by para-iodophenol. The glass microchip and poly(dimethylsiloxane) (PDMS)/glass microchip for IEF were fabricated using micromachining technology in the laboratory. The modes of CL detection were investigated and two microchips (glass, PDMS/glass) were compared. Certain proteins, such as cytochrome c, myoglobin, and horseradish peroxidase, were focused by use of Pharmalyte pH 3-10 as ampholytes. Hydroxypropylmethylcellulose was added to the sample solution in order to easily reduce protein interactions with the channel wall as well as the EOF. The focused proteins were transported by salt mobilization to the CL detection window. Cytochrome c, myoglobin, and horseradish peroxidase were well separated within 10 min on a glass chip and the detection limits (S/N=3) were 1.2x10(-7), 1.6x10(-7), and 1.0x10(-10) M, respectively.
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Affiliation(s)
- Xiangyi Huang
- College of Chemistry and Chemical Engineering, Shanghai Jiaotong University, Shanghai, P.R. China
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45
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Kostal V, Zeisbergerova M, Slais K, Kahle V. Fluorescence detection system for capillary separations utilizing a liquid core waveguide with an optical fibre-coupled compact spectrometer. J Chromatogr A 2005; 1081:36-41. [PMID: 16013595 DOI: 10.1016/j.chroma.2005.05.039] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
A fluorescence detection system for capillary liquid separation methods is described. The system is based on a silica capillary coated with a low refractive index fluoropolymer Teflon AF that serves both as a separation channel and as a liquid core waveguide (LCW). A fibre-coupled laser excites separated analytes in a detection point and arising fluorescence is collected at one end of the LCW capillary into the other optical fibre which brings it to a compact charge-coupled device (CCD) array spectrometer installed in a desktop computer. No additional components such as focusing optics or filters are necessary. This system was used for detecting isoelectrically focused fluorescent low-molecular-mass pI (isoelectric point) markers and fluorescein isothiocyanate (FITC) labelled proteins. The ability of the system to acquire fluorescent spectra is also demonstrated.
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Affiliation(s)
- Vratislav Kostal
- Department of Analytical Chemistry, Faculty of Science, Palacky University, tr. Svobody 26, 771 46 Olomouc, Czech Republic.
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46
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Liu Z, Pawliszyn J. Behaviors of the MS2 virus and related antibodies in capillary isoelectric focusing with whole-column imaging detection. Electrophoresis 2005; 26:556-62. [PMID: 15690457 DOI: 10.1002/elps.200410075] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Capillary isoelectric focusing (CIEF) has potential importance for the study of viruses. CIEF with whole-column imaging detection (WCID) is a novel CIEF mode, providing the advantages of high resolution, high speed, and easy method development. To facilitate the application of CIEF-WCID to the immunoassay of viruses, a basic knowledge of related aspects is necessary. In this study, the MS2 bacteriophage was used as a virus model, and the behaviors of MS2 and related antibodies in CIEF were investigated with UV absorbance-WCID and laser-induced fluorescence (LIF)-WCID. The adsorption of the virus and antibodies on the capillary wall was found to be the critical issue in method development. Addition of salt was found to be an effective way to reduce the adsorption and to improve peak shape. The formation of an immunocomplex, which forms the basis of an immunoassay, was monitored with CIEF-WCID. In comparison with UV-WCID, LIF-WCID was advantageous due to its higher detection sensitivity and the elimination of precipitation. Utilization of the noncovalent fluorescent dye, NanoOrange, was demonstrated to be a potential approach for the fluorescent labeling of the virus model and antibody and the associated immunocomplex. The change in microheterogeneity during the immune interactions at different ratios was also observed.
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Affiliation(s)
- Zhen Liu
- Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada
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47
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Wang SL, Fang ZL. Integrating functional components into capillary electrophoresis systems using liquid-core waveguides. Anal Bioanal Chem 2005; 382:1747-50. [PMID: 15940448 DOI: 10.1007/s00216-005-3298-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Shi-Li Wang
- Research Center for Analytical Sciences, Northeastern University, Shenyang 110004, PR China
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48
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Wu XZ, Huang T, Liu Z, Pawliszyn J. Whole-column imaging-detection techniques and their analytical applications. Trends Analyt Chem 2005. [DOI: 10.1016/j.trac.2005.02.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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49
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Sequential injection absorption spectrophotometry using a liquid-core waveguide: Determination of p-arsanilic acid in natural waters. Anal Chim Acta 2005. [DOI: 10.1016/j.aca.2005.02.067] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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50
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Liu Z, Pawliszyn J. Applications of capillary isoelectric focusing with liquid-core waveguide laser-induced fluorescence whole-column imaging detection. Anal Biochem 2005; 336:94-101. [PMID: 15582563 DOI: 10.1016/j.ab.2004.09.021] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2004] [Indexed: 10/26/2022]
Abstract
Capillary isoelectric focusing (CIEF) with liquid-core waveguide (LCW) laser-induced fluorescence (LIF) whole-column imaging detection (WCID) is a recently developed high-resolution, high-sensitivity, and high-speed analytical tool for protein analysis. Several potential applications of this system were demonstrated in this study. First, this system was employed to separate naturally fluorescent phycobiliproteins. Second, denaturing CIEF was suggested to study the conformational and chemical microheterogeneity and to characterize proteins with identical pI values. Third, a modified noncovalent fluorescent labeling procedure was presented, which allows the simple and effective labeling of proteins, antibodies, and viruses with reduced multiple labeling and preserved activity. Finally, extracellular proteins were suggested as signaling biomarkers for evaluation of cell viability. The separation of cyanobacteria and their extracellular phycoerythrins was demonstrated. The effectiveness of CIEF-LCW-LIF-WCID for the analysis of proteins, antibodies, viruses, and cells has been illustrated.
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Affiliation(s)
- Zhen Liu
- Department of Chemistry, University of Waterloo, Waterloo, Ont., Canada N2L 3G1
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