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Yang N, Kuo M, Liu J, Amirkhanian V, Tsai E. Direct SARS-CoV-2 Detection System Utilizing Simple-to-Use Capillary Gel Electrophoresis Sample-to-Result. Curr Mol Med 2024; 24:145-150. [PMID: 36336803 DOI: 10.2174/1566524023666221104160148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 10/12/2022] [Accepted: 10/13/2022] [Indexed: 11/09/2022]
Abstract
AIM We present a Direct SARS-CoV-2 Detection System that achieves sample-to-results in less than two hours in three simple steps. METHODS The Detection System includes Direct one-step Reverse Transcription PCR (RT-PCR) reagents (Qexp-MDx kit), a portable thermal cycler (Qampmini) with a preprogrammed chip and a simple-to-use Capillary Gel Electrophoresis system (Qsep Series Bio-Fragment Analyzer) with high fluorescence detection sensitivity to solve the problems associated with traditional real-time PCR (qPCR) systems which produces high false positive results. RESULTS The proposed simple-to-use detection platform can provide high detection sensitivity (identify less than 20 copies) and fast results (less than 120 minutes), which would be suitable for field testing applications. CONCLUSION Our high detection sensitivity platform provides fast and accurate results in 120 minutes without doing DNA/RNA extraction.
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Affiliation(s)
- Neo Yang
- BiOptic, Inc. (23141) 5F., No.6, Ln. 130, Minquan Rd., Xindian Dis., New Taipei City, Taiwan
| | - Meya Kuo
- BiOptic, Inc. (23141) 5F., No.6, Ln. 130, Minquan Rd., Xindian Dis., New Taipei City, Taiwan
| | - Jerry Liu
- BiOptic, Inc. (23141) 5F., No.6, Ln. 130, Minquan Rd., Xindian Dis., New Taipei City, Taiwan
| | - Varoujan Amirkhanian
- BiOptic, Inc. (23141) 5F., No.6, Ln. 130, Minquan Rd., Xindian Dis., New Taipei City, Taiwan
| | - Eric Tsai
- BiOptic, Inc. (23141) 5F., No.6, Ln. 130, Minquan Rd., Xindian Dis., New Taipei City, Taiwan
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2
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Hajba L, Jeong S, Chung DS, Guttman A. Capillary Gel Electrophoresis of Proteins: Historical overview and recent advances. Trends Analyt Chem 2023. [DOI: 10.1016/j.trac.2023.117024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2023]
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3
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Sharmeen S, Kyei I, Hatch A, Hage DS. Analysis of drug interactions with serum proteins and related binding agents by affinity capillary electrophoresis: A review. Electrophoresis 2022; 43:2302-2323. [PMID: 36250426 PMCID: PMC10098505 DOI: 10.1002/elps.202200191] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Revised: 09/17/2022] [Accepted: 10/05/2022] [Indexed: 11/06/2022]
Abstract
Biomolecules such as serum proteins can interact with drugs in the body and influence their pharmaceutical effects. Specific and precise methods that analyze these interactions are critical for drug development or monitoring and for diagnostic purposes. Affinity capillary electrophoresis (ACE) is one technique that can be used to examine the binding between drugs and serum proteins, or other agents found in serum or blood. This article will review the basic principles of ACE, along with related affinity-based capillary electrophoresis (CE) methods, and examine recent developments that have occurred in this field as related to the characterization of drug-protein interactions. An overview will be given of the various formats that can be used in ACE and CE for such work, including the relative advantages or weaknesses of each approach. Various applications of ACE and affinity-based CE methods for the analysis of drug interactions with serum proteins and other binding agents will also be presented. Applications of ACE and related techniques that will be discussed include drug interaction studies with serum agents, chiral drug separations employing serum proteins, and the use of CE in hybrid methods to characterize drug binding with serum proteins.
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Affiliation(s)
- Sadia Sharmeen
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | - Isaac Kyei
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | - Arden Hatch
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | - David S Hage
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
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4
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Opallage PM, De Silva M, Dunn RC. Dual detection high-speed capillary electrophoresis for simultaneous serum protein analysis and immunoassays. Sci Rep 2022; 12:1951. [PMID: 35121780 PMCID: PMC8817013 DOI: 10.1038/s41598-022-05956-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 01/17/2022] [Indexed: 11/09/2022] Open
Abstract
Serum protein electrophoresis (SPE) separates serum proteins into bands whose shape and amplitude can alert clinicians to a range of disorders. This is followed by more specific immunoassays to quantify important antigens and confirm a diagnosis. Here we develop a high-speed capillary electrophoresis (HSCE) platform capable of simultaneous SPE and immunoassay measurements. A single laser excitation source is focused into the detection zone of the capillary to measure both refractive index (SPE) and fluorescence signals (immunoassays). The refractive index signal measures characteristic SPE profiles for human serum separated in 100 mM boric acid (pH 10), 100 mM arginine (pH 11), and 20 mM CHES (pH 10). For the immunoassay, the fluorescence electropherograms reveal that CHES provides the optimal buffer for measuring the immunocomplex and separating it from the free antigen. Immunoassays in CHES yield a LOD of 23 nM and a LOQ of 70 nM for the detection of fluorescein. The high pH reduces protein adsorption but reduces antibody affinity. Preliminary studies carried out in 50 mM barbital at pH 8 show improved stability of the immunocomplex and better separation for immunoassay quantification. Further optimization will open new capabilities for measuring orthogonal diagnostic signals in seconds with HSCE.
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Affiliation(s)
- Prabhavie M Opallage
- Ralph N. Adams Institute for Bioanalytical Chemistry, Department of Chemistry, University of Kansas, 2030 Becker Drive, Lawrence, KS, 66047, USA
| | - Miyuru De Silva
- Ralph N. Adams Institute for Bioanalytical Chemistry, Department of Chemistry, University of Kansas, 2030 Becker Drive, Lawrence, KS, 66047, USA
| | - Robert C Dunn
- Ralph N. Adams Institute for Bioanalytical Chemistry, Department of Chemistry, University of Kansas, 2030 Becker Drive, Lawrence, KS, 66047, USA.
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5
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Zinc-Finger-Protein-Based Microfluidic Electrophoretic Mobility Reversal Assay for Quantitative Double-Stranded DNA Analysis. BIOCHIP JOURNAL 2021. [DOI: 10.1007/s13206-021-00038-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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6
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Nevídalová H, Michalcová L, Glatz Z. Capillary electrophoresis-based immunoassay and aptamer assay: A review. Electrophoresis 2020; 41:414-433. [PMID: 31975407 DOI: 10.1002/elps.201900426] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2019] [Revised: 01/14/2020] [Accepted: 01/15/2020] [Indexed: 12/31/2022]
Abstract
Over the last two decades, the group of techniques called affinity probe CE has been widely used for the detection and the determination of several types of biomolecules with high sensitivity. These techniques combine the low sample consumption and high separation power of CE with the selectivity of the probe to the target molecule. The assays can be defined according to the type of probe used: CE immunoassays, with an antibody as the probe, or aptamer-based CE, with an aptamer as the probe. Immunoassays are generally divided into homogeneous and heterogeneous groups, and homogeneous variant can be further performed in competitive or noncompetitive formats. Interacting partners are free in solution at homogeneous assay, as opposed to heterogeneous analyses, where one of them is immobilized onto a solid support. Highly sensitive fluorescence, chemiluminescence or electrochemical detections were typically used in this type of study. The use of the aptamers as probes has several advantages over antibodies such as shorter generation time, higher thermal stability, lower price, and lower variability. The aptamer-based CE technique was in practice utilized for the determination of proteins in biological fluids and environmentally or clinically important small molecules. Both techniques were also transferred to microchip. This review is focused on theoretical principles of these techniques and a summary of their applications in research.
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Affiliation(s)
- Hana Nevídalová
- Department of Biochemistry, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Lenka Michalcová
- Department of Biochemistry, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Zdeněk Glatz
- Department of Biochemistry, Faculty of Science, Masaryk University, Brno, Czech Republic
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7
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Lee SB, Han YR, Jeon HJ, Jun CH, Kim SK, Chin J, Lee SJ, Jeong M, Lee JE, Lee CH, Cho SJ, Kim DS, Jeon YH. Medical fluorophore 1 (MF1), a benzoquinolizinium-based fluorescent dye, as an inflammation imaging agent. J Mater Chem B 2019; 7:7326-7331. [PMID: 31681930 DOI: 10.1039/c9tb01266d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Structure-based targeting of fluorescent dyes is essential for their use as imaging agents for disease diagnosis. Here, we describe the development of the benzoquinolizinium compound Medical fluorophore 1 (MF1) as a novel biomedical imaging agent that allows the visualization of inflammation by virtue of its unique chemical structure. Lipopolysaccharide treatment stimulated the uptake of MF1 by bone marrow-derived macrophages, with no adverse effects on cell proliferation. In vivo fluorescence lifetime imaging revealed the accumulation of MF1 in carrageenan-induced acute inflammatory lesions in mice, which peaked at 6 h. MF1-based imaging also allowed monitoring of the response to the anti-inflammatory drugs dexamethasone and sulfasalazine. Thus, MF1 can be used to diagnose diseases characterized by inflammation as well as treatment efficacy.
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Affiliation(s)
- Sang Bong Lee
- New Drug Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, 80 Chembok-ro Dong-gu Daegu, Republic of Korea.
| | - Ye Ri Han
- New Drug Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, 80 Chembok-ro Dong-gu Daegu, Republic of Korea.
| | - Hui-Jeon Jeon
- New Drug Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, 80 Chembok-ro Dong-gu Daegu, Republic of Korea.
| | - Chul-Ho Jun
- Department of Chemistry, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea and Center for NanoMedicine, Institute for Basic Science (IBS), Seoul, Republic of Korea and Yonsei-IBS Institute, Yonsei University, Seoul 03722, Republic of Korea
| | - Sang-Kyoon Kim
- Laboratory Animal Center, Daegu-Gyeongbuk Medical Innovation Foundation, 80 Chembok-ro Dong-gu Daegu, Republic of Korea.
| | - Jungwook Chin
- New Drug Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, 80 Chembok-ro Dong-gu Daegu, Republic of Korea.
| | - Su-Jeong Lee
- New Drug Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, 80 Chembok-ro Dong-gu Daegu, Republic of Korea.
| | - Minseon Jeong
- New Drug Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, 80 Chembok-ro Dong-gu Daegu, Republic of Korea.
| | - Jae-Eon Lee
- Laboratory Animal Center, Daegu-Gyeongbuk Medical Innovation Foundation, 80 Chembok-ro Dong-gu Daegu, Republic of Korea. and Department of Biomaterials Science, College of Natural Resources and Life Science/Life and Industry Convergence Research Institute, Pusan National University, Pusan, Republic of Korea
| | - Chang-Hee Lee
- Department of Chemistry, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea and Center for NanoMedicine, Institute for Basic Science (IBS), Seoul, Republic of Korea and Yonsei-IBS Institute, Yonsei University, Seoul 03722, Republic of Korea
| | - Sung Jin Cho
- New Drug Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, 80 Chembok-ro Dong-gu Daegu, Republic of Korea.
| | - Dong-Su Kim
- New Drug Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, 80 Chembok-ro Dong-gu Daegu, Republic of Korea.
| | - Yong Hyun Jeon
- Laboratory Animal Center, Daegu-Gyeongbuk Medical Innovation Foundation, 80 Chembok-ro Dong-gu Daegu, Republic of Korea.
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8
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Ouimet CM, Dawod M, Grinias J, Assimon VA, Lodge J, Mapp AK, Gestwicki JE, Kennedy RT. Protein cross-linking capillary electrophoresis at increased throughput for a range of protein-protein interactions. Analyst 2019; 143:1805-1812. [PMID: 29565056 DOI: 10.1039/c7an02098h] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Tools for measuring affinities and stoichiometries of protein-protein complexes are valuable for elucidating the role of protein-protein interactions (PPIs) in governing cell functions and screening for PPI modulators. Such measurements can be challenging because PPIs can span a wide range of affinities and include stoichiometries from dimers to high order oligomers. Also, most techniques require large amounts of protein which can hamper research for difficult to obtain proteins. Protein cross-linking capillary electrophoresis (PXCE) has the potential to directly measure PPIs and even resolve multiple PPIs while consuming attomole quantities. Previously PXCE has only been used for high affinity, 1 : 1 complexes; here we expand the utility of PXCE to access a wide range of PPIs including weak and multimeric oligomers. Use of glutaraldehyde as the cross-linking agent was key to advancing the method because of its rapid reaction kinetics. A 10 s reaction time was found to be sufficient for cross-linking and quantification of seven different PPIs with Kd values ranging from low μM to low nM including heat shock protein 70 (Hsp70) interacting with heat shock organizing protein (3.8 ± 0.7 μM) and bcl2 associated anthanogene (26 ± 6 nM). Non-specific cross-linking of protein aggregates was found to be minimal at protein concentrations <20 μM as assessed by size exclusion chromatography. PXCE was sensitive enough to measure changes in PPI affinity induced by the protein nucleotide state or point mutations in the protein-binding site. Further, several interactions could be resolved in a single run, including Hsp70 monomer, homodimer and Hsp70 complexed the with c-terminus of Hsp70 interacting protein (CHIP). Finally, the throughput of PXCE was increased to 1 min per sample suggesting potential for utility in screening.
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Affiliation(s)
- Claire M Ouimet
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Mohamed Dawod
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA.
| | - James Grinias
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA. and Department of Chemistry, Rowan University, Glassboro, NJ 08028, USA
| | - Victoria A Assimon
- Department of Pharmaceutical Chemistry, University of California at San Francisco, California 94158, USA
| | - Jean Lodge
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Anna K Mapp
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA. and Program in Chemical Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Jason E Gestwicki
- Department of Pharmaceutical Chemistry, University of California at San Francisco, California 94158, USA
| | - Robert T Kennedy
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA. and Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
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9
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Usuki S, Yamatoya K, Kawamura Y, Yamaguchi Y, Suzuki N, Katsumata KI, Terashima C, Fujishima A, Kudo A, Nakata K. Denaturation of Lysozyme with Visible-light-responsive Photocatalysts of Ground Rhodium-doped and Ground Rhodium-antimony-co-doped Strontium Titanate. J Oleo Sci 2018; 67:1521-1533. [PMID: 30504623 DOI: 10.5650/jos.ess18155] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Protein denaturants play an important role in medical and biological research, and development of new denaturants is widely explored to study aging and various diseases. In this research, we treated lysozyme, a model protein, with photocatalysts of ground Rh-doped SrTiO3 (g-STO:Rh) and ground Rh-Sb-co-doped SrTiO3 (g-STO:Rh/Sb) under visible light irradiation to explore the potential of those photocatalysts as denaturants. SDS-PAGE showed that photocatalysis with g-STO:Rh induced the fragmentation of lysozyme into unidentifiable decomposition products. BCA and Bradford protein assays indicated that the peptide bonds and basic, aromatic and N-terminal amino acid residues in lysozyme were denaturated by g-STO:Rh photocatalysis. The denaturation of those amino acids, as quantified by the decreased solubility of lysozyme, was estimated to be more severe by Bradford protein assay than by BCA protein assay. Circular dichroism (CD) spectra of lysozyme revealed that the secondary structure was denatured by g-STO:Rh photocatalysis, indicating that g-STO:Rh photocatalysis is especially effective against the amino acid residues that form the secondary structure via hydrogen bonds. Furthermore, the lytic activity of lysozyme was reduced by g-STO:Rh photocatalysis, owing to denaturation of the enzyme. The visible-light-responsive photocatalyst of g-STO:Rh/Sb accelerates the oxidation reaction and has stronger oxidizing power than g-STO:Rh. Lysozyme was denatured more quickly by g-STO:Rh/Sb photocatalysis than by g-STO:Rh according to analysis by SDS-PAGE, CD spectroscopy, BCA and Bradford protein assays, and lytic activity. These results suggest that higher photocatalytic activity induces more significant denaturation of lysozyme, implying that the main factor of photocatalytic denaturation of lysozyme is oxidation. It should be noted that, as far as we know, this is the first report for denaturation of protein using visible-light-responsive photocatalyst.
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Affiliation(s)
- Sho Usuki
- Photocatalysis International Research Center, Research Institute for Science and Technology, Tokyo University of Science.,Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science
| | - Kenji Yamatoya
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science
| | - Yuki Kawamura
- Photocatalysis International Research Center, Research Institute for Science and Technology, Tokyo University of Science.,Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science
| | - Yuichi Yamaguchi
- Photocatalysis International Research Center, Research Institute for Science and Technology, Tokyo University of Science.,Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science
| | - Norihiro Suzuki
- Photocatalysis International Research Center, Research Institute for Science and Technology, Tokyo University of Science
| | - Ken-Ichi Katsumata
- Photocatalysis International Research Center, Research Institute for Science and Technology, Tokyo University of Science
| | - Chiaki Terashima
- Photocatalysis International Research Center, Research Institute for Science and Technology, Tokyo University of Science
| | - Akira Fujishima
- Photocatalysis International Research Center, Research Institute for Science and Technology, Tokyo University of Science
| | - Akihiko Kudo
- Photocatalysis International Research Center, Research Institute for Science and Technology, Tokyo University of Science.,Department of Applied Chemistry, Faculty of Science, Tokyo University of Science
| | - Kazuya Nakata
- Photocatalysis International Research Center, Research Institute for Science and Technology, Tokyo University of Science.,Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science
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10
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Moser AC, Trenhaile S, Frankenberg K. Studies of antibody-antigen interactions by capillary electrophoresis: A review. Methods 2018; 146:66-75. [DOI: 10.1016/j.ymeth.2018.03.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Revised: 03/08/2018] [Accepted: 03/13/2018] [Indexed: 11/25/2022] Open
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11
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Nguyen BT, Park M, Yoo YS, Kang MJ. Capillary electrophoresis-laser-induced fluorescence (CE-LIF)-based immunoassay for quantifying antibodies against cyclic citrullinated peptides. Analyst 2018; 143:3141-3147. [DOI: 10.1039/c8an00714d] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
CE-LIF based immunoassay to quantify antibodies against cyclic citrullinated peptides in rheumatoid arthritis patients.
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Affiliation(s)
- Binh Thanh Nguyen
- Molecular Recognition Research Center
- Korea Institute of Science and Technology (KIST)
- Seoul 02792
- Korea
- Division of Bio-Medical Science and Technology (Biological Chemistry)
| | - Min Park
- Department of Materials Science and Engineering
- Hallym University
- Chuncheon-si
- Korea
- Integrative Materials Research Institute
| | - Young Sook Yoo
- Molecular Recognition Research Center
- Korea Institute of Science and Technology (KIST)
- Seoul 02792
- Korea
| | - Min-Jung Kang
- Molecular Recognition Research Center
- Korea Institute of Science and Technology (KIST)
- Seoul 02792
- Korea
- Division of Bio-Medical Science and Technology (Biological Chemistry)
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12
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Ouimet CM, D’Amico CI, Kennedy RT. Advances in capillary electrophoresis and the implications for drug discovery. Expert Opin Drug Discov 2017; 12:213-224. [PMID: 27911223 PMCID: PMC5521262 DOI: 10.1080/17460441.2017.1268121] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
INTRODUCTION Many screening platforms are prone to assay interferences that can be avoided by directly measuring the target or enzymatic product. Capillary electrophoresis (CE) and microchip electrophoresis (MCE) have been applied in a variety of formats to drug discovery. CE provides direct detection of the product allowing for the identification of some forms of assay interference. The high efficiency, rapid separations, and low volume requirements make CE amenable to drug discovery. Areas covered: This article describes advances in capillary electrophoresis throughput, sample introduction, and target assays as they pertain to drug discovery and screening. Instrumental advances discussed include integrated droplet microfluidics platforms and multiplexed arrays. Applications of CE to assays of diverse drug discovery targets, including enzymes and affinity interactions are also described. Expert opinion: Current screening with CE does not fully take advantage of the throughputs or low sample volumes possible with CE and is most suitable as a secondary screening method or for screens that are inaccessible with more common platforms. With further development, droplet microfluidics coupled to MCE could take advantage of the low sample requirements by performing assays on the nanoliter scale at high throughput.
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Affiliation(s)
- Claire M. Ouimet
- Department of Chemistry, University of Michigan, 930 N. University Ave, Ann Arbor, MI, 48109, United States
| | - Cara I. D’Amico
- Department of Pharmacology, University of Michigan, 1150 W. Medical Center Dr., Ann Arbor, MI, 48109, United States
| | - Robert T. Kennedy
- Department of Chemistry, University of Michigan, 930 N. University Ave, Ann Arbor, MI, 48109, United States
- Department of Pharmacology, University of Michigan, 1150 W. Medical Center Dr., Ann Arbor, MI, 48109, United States
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13
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Yi L, Wang X, Bethge L, Klussmann S, Roper MG. Noncompetitive affinity assays of glucagon and amylin using mirror-image aptamers as affinity probes. Analyst 2017; 141:1939-46. [PMID: 26881276 DOI: 10.1039/c5an02468d] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The ability to detect picomolar concentrations of glucagon and amylin using fluorescently labeled mirror-image aptamers, so-called Spiegelmers, is demonstrated. Spiegelmers rival the specificity of antibodies and overcome the problem of biostability of natural aptamers in a biological matrix. Using Spiegelmers as affinity probes, noncompetitive capillary electrophoresis affinity assays of glucagon and murine amylin were developed and optimized. The detection limit for glucagon was 6 pM and for amylin was 40 pM. Glucagon-like peptide-1 and -2 did not interfere with the glucagon assay, while the amylin assay showed cross-reactivity to calcitonin gene related peptide. The developed assays were combined with a competitive immunoassay for insulin to measure glucagon, amylin, and insulin secretion from batches of islets after incubation with different glucose concentrations. The development of these assays is an important step towards incorporation into an online measurement system for monitoring dynamic secretion from single islets.
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Affiliation(s)
- Lian Yi
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftain Way, Dittmer Building, Tallahassee, FL 32306, USA.
| | - Xue Wang
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftain Way, Dittmer Building, Tallahassee, FL 32306, USA.
| | - Lucas Bethge
- NOXXON Pharma AG, Max-Dohrn-Str. 8-10, 10589 Berlin, Germany
| | - Sven Klussmann
- NOXXON Pharma AG, Max-Dohrn-Str. 8-10, 10589 Berlin, Germany
| | - Michael G Roper
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftain Way, Dittmer Building, Tallahassee, FL 32306, USA.
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14
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Shimura K, Nagai T. Capillary isoelectric focusing after sample enrichment with immunoaffinity chromatography in a single capillary. Sci Rep 2016; 6:39221. [PMID: 27976690 PMCID: PMC5156949 DOI: 10.1038/srep39221] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 11/21/2016] [Indexed: 11/12/2022] Open
Abstract
For accurate micro-scale quantification of a specific protein in biological fluids, immunoaffinity chromatography (IAC) and isoelectric focusing (IEF) were combined in a single fused-silica capillary. The inner wall of the capillary was coated with an anti-E-tag antibody at the inlet side to form an IAC column, and polydimethylacrylamide, a neutral polymer, at the outlet side to form the capillary for IEF. After loading a sample, the whole capillary was filled with a carrier ampholyte solution. An anode solution, an acid, was then introduced to fill only the IAC column segment. Focusing was started with a pressure that balances with the electroosmotic flow produced in the acidified IAC column. Fluorescence-labeled recombinant Fab with an E-tag spiked at 16 pM to 10 nM in 50% serum was separated and detected with high precision. The coupling principle allows rapid and high-resolution IEF analysis of a protein in a biological sample without any loss of the immunoaffinity captured protein.
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Affiliation(s)
- Kiyohito Shimura
- Division of Advanced Chemistry, Fukushima Medical University, 1 Hikarigaoka, Fukushima, 960-1295, Japan
| | - Toshihiko Nagai
- Division of Advanced Chemistry, Fukushima Medical University, 1 Hikarigaoka, Fukushima, 960-1295, Japan
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15
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Ouimet CM, Shao H, Rauch JN, Dawod M, Nordhues B, Dickey CA, Gestwicki JE, Kennedy RT. Protein Cross-Linking Capillary Electrophoresis for Protein-Protein Interaction Analysis. Anal Chem 2016; 88:8272-8. [PMID: 27434096 DOI: 10.1021/acs.analchem.6b02126] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Capillary electrophoresis (CE) has been identified as a useful platform for detecting, quantifying, and screening for modulators of protein-protein interactions (PPIs). In this method, one protein binding partner is labeled with a fluorophore, the protein binding partners are mixed, and then, the complex is separated from free protein to allow direct determination of bound to free ratios. Although it possesses many advantages for PPI studies, the method is limited by the need to have separation conditions that both prevent protein adsorption to capillary and maintain protein interactions during the separation. In this work, we use protein cross-linking capillary electrophoresis (PXCE) to overcome this limitation. In PXCE, the proteins are cross-linked under binding conditions and then separated. This approach eliminates the need to maintain noncovalent interactions during electrophoresis and facilitates method development. We report PXCE methods for an antibody-antigen interaction and heterodimer and homodimer heat shock protein complexes. Complexes are cross-linked by short treatments with formaldehyde after reaching binding equilibrium. Cross-linked complexes are separated by electrophoretic mobility using free solution CE or by size using sieving electrophoresis of SDS complexes. The method gives good quantitative results; e.g., a lysozyme-antibody interaction was found to have Kd = 24 ± 3 nM by PXCE and Kd = 17 ± 2 nM using isothermal calorimetry (ITC). Heat shock protein 70 (Hsp70) in complex with bcl2 associated athanogene 3 (Bag3) was found to have Kd = 25 ± 5 nM by PXCE which agrees with Kd values reported without cross-linking. Hsp70-Bag3 binding site mutants and small molecule inhibitors of Hsp70-Bag3 were characterized by PXCE with good agreement to inhibitory constants and IC50 values obtained by a bead-based flow cytometry protein interaction assay (FCPIA). PXCE allows rapid method development for quantitative analysis of PPIs.
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Affiliation(s)
- Claire M Ouimet
- Department of Chemistry, University of Michigan , 930 N. University Ave., Ann Arbor, Michigan 48109, United States
| | - Hao Shao
- Department of Pharmaceutical Chemistry and the Institute for Neurodegenerative Disease, University of California at San Francisco , 675 Nelson Rising Ln., San Francisco, California 94158, United States
| | - Jennifer N Rauch
- Department of Pharmaceutical Chemistry and the Institute for Neurodegenerative Disease, University of California at San Francisco , 675 Nelson Rising Ln., San Francisco, California 94158, United States
| | - Mohamed Dawod
- Department of Chemistry, University of Michigan , 930 N. University Ave., Ann Arbor, Michigan 48109, United States
| | - Bryce Nordhues
- Department of Molecular Medicine, University of South Florida , 4001 E. Fletcher Ave., MDC 36, Tampa, Florida 33613, United States
| | - Chad A Dickey
- Department of Molecular Medicine, University of South Florida , 4001 E. Fletcher Ave., MDC 36, Tampa, Florida 33613, United States
| | - Jason E Gestwicki
- Department of Pharmaceutical Chemistry and the Institute for Neurodegenerative Disease, University of California at San Francisco , 675 Nelson Rising Ln., San Francisco, California 94158, United States
| | - Robert T Kennedy
- Department of Chemistry, University of Michigan , 930 N. University Ave., Ann Arbor, Michigan 48109, United States.,Department of Pharmacology, University of Michigan , 1150 W. Medical Center Dr., Ann Arbor, Michigan 48109, United States
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16
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Schrell AM, Mukhitov N, Yi L, Wang X, Roper MG. Microfluidic Devices for the Measurement of Cellular Secretion. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2016; 9:249-69. [PMID: 27306310 DOI: 10.1146/annurev-anchem-071114-040409] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The release of chemical information from cells and tissues holds the key to understanding cellular behavior and dysfunction. The development of methodologies that can measure cellular secretion in a time-dependent fashion is therefore essential. Often these measurements are made difficult by the high-salt conditions of the cellular environment, the presence of numerous other secreted factors, and the small mass samples that are produced when frequent sampling is used to resolve secretory dynamics. In this review, the methods that we have developed for measuring hormone release from islets of Langerhans are dissected to illustrate the practical difficulties of studying cellular secretions. Other methods from the literature are presented that provide alternative approaches to particularly challenging areas of monitoring cellular secretion. The examples presented in this review serve as case studies and should be adaptable to other cell types and systems for unique applications.
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Affiliation(s)
- Adrian M Schrell
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306;
| | - Nikita Mukhitov
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306;
| | - Lian Yi
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306;
| | - Xue Wang
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306;
| | - Michael G Roper
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306;
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17
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Klepárník K, Datinská V, Voráčová I, Lišková M. Analysis of quantum dots and their conjugates by capillary electrophoresis with detection of laser-induced luminescence. Methods Mol Biol 2015; 1199:33-54. [PMID: 25103798 DOI: 10.1007/978-1-4939-1280-3_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
In many bioanalytical applications, important molecules such as DNA, proteins, and antibodies are routinely conjugated with fluorescent tags to reach an extraordinary sensitivity of analyses. Semiconductor nanoparticles, quantum dots, have already proved to be suitable components of highly luminescent tags, probes, and sensors with a broad applicability in analytical chemistry. Quantum dots provide high extinction coefficients together with a wide range of excitation wavelengths, size- and composition-tunable emissions, narrow and symmetric emission spectra, good quantum yields, relatively long size-dependent luminescence lifetime, and practically no photobleaching. Most of these properties are superior when compared with conventional organic fluorescent dyes. In this chapter, optimized procedures for the preparation of water-dispersed cadmium telluride (CdTe) quantum dots, conjugating reactions with antibodies, DNA, and macrocycles as well as their analyses by capillary electrophoresis are described. The potential of capillary electrophoresis for fast analyses of nanoparticles, their conjugates with antibodies, and immunocomplexes with targeted antigens is demonstrated on examples.
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Affiliation(s)
- Karel Klepárník
- Institute of Analytical Chemistry, Czech Academy of Sciences, Veveří 97, 602 00, Brno, Czech Republic,
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18
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Kinoshita E, Kinoshita-Kikuta E, Koike T. The Cutting Edge of Affinity Electrophoresis Technology. Proteomes 2015; 3:42-55. [PMID: 28248262 PMCID: PMC5302491 DOI: 10.3390/proteomes3010042] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Revised: 01/26/2015] [Accepted: 03/11/2015] [Indexed: 11/16/2022] Open
Abstract
Affinity electrophoresis is an important technique that is widely used to separate and analyze biomolecules in the fields of biology and medicine. Both quantitative and qualitative information can be gained through affinity electrophoresis. Affinity electrophoresis can be applied through a variety of strategies, such as mobility shift electrophoresis, charge shift electrophoresis or capillary affinity electrophoresis. These strategies are based on changes in the electrophoretic patterns of biological macromolecules that result from interactions or complex-formation processes that induce changes in the size or total charge of the molecules. Nucleic acid fragments can be characterized through their affinity to other molecules, for example transcriptional factor proteins. Hydrophobic membrane proteins can be identified by means of a shift in the mobility induced by a charged detergent. The various strategies have also been used in the estimation of association/disassociation constants. Some of these strategies have similarities to affinity chromatography, in that they use a probe or ligand immobilized on a supported matrix for electrophoresis. Such methods have recently contributed to profiling of major posttranslational modifications of proteins, such as glycosylation or phosphorylation. Here, we describe advances in analytical techniques involving affinity electrophoresis that have appeared during the last five years.
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Affiliation(s)
- Eiji Kinoshita
- Department of Functional Molecular Science, Institute of Biomedical and Health Sciences, Hiroshima University, Kasumi 1-2-3, Hiroshima 734-8553, Japan.
| | - Emiko Kinoshita-Kikuta
- Department of Functional Molecular Science, Institute of Biomedical and Health Sciences, Hiroshima University, Kasumi 1-2-3, Hiroshima 734-8553, Japan.
| | - Tohru Koike
- Department of Functional Molecular Science, Institute of Biomedical and Health Sciences, Hiroshima University, Kasumi 1-2-3, Hiroshima 734-8553, Japan.
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19
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Shimura K, Nagai T. Direct coupling of immobilized metal ion affinity chromatography and capillary isoelectric focusing in a single capillary. ACTA ACUST UNITED AC 2015. [DOI: 10.2198/jelectroph.59.7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Kiyohito Shimura
- Division of Advanced Chemistry, School of Medicine, Fukushima Medical University
| | - Toshihiko Nagai
- Division of Advanced Chemistry, School of Medicine, Fukushima Medical University
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20
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Mukhitov N, Yi L, Schrell AM, Roper MG. Optimization of a microfluidic electrophoretic immunoassay using a Peltier cooler. J Chromatogr A 2014; 1367:154-60. [PMID: 25263064 DOI: 10.1016/j.chroma.2014.09.040] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Revised: 09/12/2014] [Accepted: 09/16/2014] [Indexed: 01/06/2023]
Abstract
Successful analysis of electrophoretic affinity assays depends strongly on the preservation of the affinity complex during separations. Elevated separation temperatures due to Joule heating promotes complex dissociation leading to a reduction in sensitivity. Affinity assays performed in glass microfluidic devices may be especially prone to this problem due to poor heat dissipation due to the low thermal conductivity of glass and the large amount of bulk material surrounding separation channels. To address this limitation, a method to cool a glass microfluidic chip for performing an affinity assay for insulin was achieved by a Peltier cooler localized over the separation channel. The Peltier cooler allowed for rapid stabilization of temperatures, with 21°C the lowest temperature that was possible to use without producing detrimental thermal gradients throughout the device. The introduction of cooling improved the preservation of the affinity complex, with even passive cooling of the separation channel improving the amount of complex observed by 2-fold. Additionally, the capability to thermostabilize the separation channel allowed for utilization of higher separation voltages than what was possible without temperature control. Kinetic CE analysis was utilized as a diagnostic of the affinity assay and indicated that optimal conditions were at the highest separation voltage, 6 kV, and the lowest separation temperature, 21°C, leading to 3.4% dissociation of the complex peak during the separation. These optimum conditions were used to generate a calibration curve and produced 1 nM limits of detection, representing a 10-fold improvement over non-thermostated conditions. This methodology of cooling glass microfluidic devices for performing robust and high sensitivity affinity assays on microfluidic systems should be amenable in a number of applications.
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Affiliation(s)
- Nikita Mukhitov
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftain Way, Dittmer Building, Tallahassee, FL 32306, United States
| | - Lian Yi
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftain Way, Dittmer Building, Tallahassee, FL 32306, United States
| | - Adrian M Schrell
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftain Way, Dittmer Building, Tallahassee, FL 32306, United States
| | - Michael G Roper
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftain Way, Dittmer Building, Tallahassee, FL 32306, United States.
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21
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Moser AC, Willicott CW, Hage DS. Clinical applications of capillary electrophoresis based immunoassays. Electrophoresis 2014; 35:937-55. [PMID: 24132682 PMCID: PMC3975666 DOI: 10.1002/elps.201300421] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 09/27/2013] [Accepted: 10/03/2013] [Indexed: 12/17/2022]
Abstract
Immunoassays have long been an important set of tools in clinical laboratories for the detection, diagnosis, and treatment of disease. Over the last two decades, there has been growing interest in utilizing CE as a means for conducting immunoassays with clinical samples. The resulting method is known as a CE immunoassay. This approach makes use of the selective and strong binding of antibodies for their targets, as is employed in a traditional immunoassay, and combines this with the speed, efficiency, and small sample requirements of CE. This review discusses the variety of ways in which CE immunoassays have been employed with clinical samples. An overview of the formats and detection modes that have been employed in these applications is first presented. A more detailed discussion is then given on the type of clinical targets and samples that have been measured or studied by using CE immunoassays. Particular attention is given to the use of this method in the fields of endocrinology, pharmaceutical measurements, protein and peptide analysis, immunology, infectious disease detection, and oncology. Representative applications in each of these areas are described, with these examples involving work with both traditional and microanalytical CE systems.
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Affiliation(s)
| | | | - David S. Hage
- Chemistry Department, University of Nebraska, Lincoln, NE
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22
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Simultaneous quantitation of 5- and 7-hydroxyflavone antioxidants and their binding constants with BSA using dual chiral capillary electrophoresis (dCCE) and HPLC with fluorescent detection. Talanta 2014; 119:417-24. [DOI: 10.1016/j.talanta.2013.11.029] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Revised: 11/06/2013] [Accepted: 11/08/2013] [Indexed: 12/27/2022]
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23
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Shimura K, Kasai KI. Affinity probe capillary electrophoresis of insulin using a fluorescence-labeled recombinant Fab as an affinity probe. Electrophoresis 2013; 35:840-5. [DOI: 10.1002/elps.201300464] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2013] [Revised: 10/21/2013] [Accepted: 11/26/2013] [Indexed: 11/07/2022]
Affiliation(s)
- Kiyohito Shimura
- Laboratory of Chemistry; School of Medicine, Fukushima Medical University; Fukushima Fukushima Japan
| | - Ken-Ichi Kasai
- Department of Biological Chemistry; Faculty of Pharmaceutical Sciences, Teikyo University; Sagamihara Kanagawa Japan
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24
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Rauch JN, Nie J, Buchholz TJ, Gestwicki JE, Kennedy RT. Development of a capillary electrophoresis platform for identifying inhibitors of protein-protein interactions. Anal Chem 2013; 85:9824-31. [PMID: 24060167 DOI: 10.1021/ac4023082] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Methods for identifying chemical inhibitors of protein-protein interactions (PPIs) are often prone to discovery of false positives, particularly those caused by molecules that induce protein aggregation. Thus, there is interest in developing new platforms that might allow earlier identification of these problematic compounds. Capillary electrophoresis (CE) has been evaluated as a method to screen for PPI inhibitors using the challenging system of Hsp70 interacting with its co-chaperone Bag3. In the method, Hsp70 is labeled with a fluorophore, mixed with Bag3, and the resulting bound and free Hsp70 are separated and detected by CE with laser-induced fluorescence detection. The method used a chemically modified CE capillary to prevent protein adsorption. Inhibitors of the Hsp70-Bag3 interaction were detected by observing a reduction in the bound-to-free ratio. The method was used to screen a library of 3443 compounds, and the results were compared to those from a flow cytometry protein interaction assay. CE was found to produce a lower hit rate with more compounds that were reconfirmed in subsequent testing, suggesting greater specificity. This finding was attributed to the use of electropherograms to detect artifacts such as aggregators and to differences in protein modifications required to perform the different assays. Increases in throughput are required to make the CE method suitable for primary screens, but at the current stage of development it is attractive as a secondary screen to test hits found by higher-throughput methods.
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Affiliation(s)
- Jennifer N Rauch
- Department of Biological Chemistry, ‡Department of Chemistry, and the§ Life Sciences Institute, University of Michigan , Ann Arbor, Michigan 48109, United States
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25
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Duncombe TA, Herr AE. Use of Polyacrylamide Gel Moving Boundary Electrophoresis to Enable Low-Power Protein Analysis in a Compact Microdevice. Anal Chem 2012; 84:8740-7. [DOI: 10.1021/ac301875e] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Todd A. Duncombe
- University of California, Berkeley−University of California, San Francisco
Graduate Program
in Bioengineering, 342 Stanley Hall, Berkeley, California 94720, United
States
| | - Amy E. Herr
- University of California, Berkeley−University of California, San Francisco
Graduate Program
in Bioengineering, 342 Stanley Hall, Berkeley, California 94720, United
States
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26
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Kiessig S, Stettler A, Fuhrimann S, Schwarz MA. Affinity Capillary Electrophoresis as a Tool to Characterize Intermolecular Interactions. Supramol Chem 2012. [DOI: 10.1002/9780470661345.smc035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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27
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Rapid determination of multidrug resistance-associated protein in cancer cells by capillary electrophoresis immunoassay. J Chromatogr A 2011; 1218:3923-7. [DOI: 10.1016/j.chroma.2011.04.046] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Revised: 04/14/2011] [Accepted: 04/17/2011] [Indexed: 11/20/2022]
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28
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Klepárník K, Voráčová I, Lišková M, Přikryl J, Hezinová V, Foret F. Capillary electrophoresis immunoassays with conjugated quantum dots. Electrophoresis 2011; 32:1217-23. [PMID: 21500216 DOI: 10.1002/elps.201000652] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Revised: 01/12/2011] [Accepted: 01/12/2011] [Indexed: 11/06/2022]
Abstract
Water-soluble CdTe quantum dots (QDs) and their conjugates with antibodies and antigenes were prepared by optimized procedures for applications in CE immunoassays. The QD size of 3.5 nm, excitation spectrum in the range of 300-500 nm, the maximum wavelength of the emission spectrum at 610 nm, quantum yield of 0.25 and luminescence lifetimes in the range of 3.6-43 ns were determined. The 0.1 M solution of TRIS/TAPS (pH 8.3) was found to be the optimum buffer for the separation of the antiovalbumin-ovalbumin immunocomplex from the free conjugates of QDs.
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Affiliation(s)
- Karel Klepárník
- Institute of Analytical Chemistry, Czech Academy of Sciences, Brno, Czech Republic.
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29
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30
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Lišková M, Voráčová I, Klepárník K, Hezinová V, Přikryl J, Foret F. Conjugation reactions in the preparations of quantum dot-based immunoluminescent probes for analysis of proteins by capillary electrophoresis. Anal Bioanal Chem 2011; 400:369-79. [PMID: 21298420 DOI: 10.1007/s00216-011-4700-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Revised: 01/06/2011] [Accepted: 01/18/2011] [Indexed: 02/07/2023]
Abstract
A number of biologically important molecules, such as DNA, proteins, and antibodies, are routinely conjugated with fluorescent tags for high-sensitivity analyses. Here, the application of quantum dots in the place of bright and size-tunable luminophores is studied. Several selected bioconjugation reactions via zero-length cross-linkers, long-chain linkers, and oriented methods for linking of quantum dots with proteins were tested. Anti-ovalbumin, anti-proliferating cell nuclear antigen, anti-hemagglutinin, and anti-CD3 membrane protein as model antibodies and annexin V were used as high-specificity selectors. The reaction yield and efficiency of the prepared immunoluminescent probes were tested by capillary zone electrophoresis with laser-induced fluorescence detection.
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Affiliation(s)
- M Lišková
- Institute of Analytical Chemistry, Academy of Sciences of the Czech Republic, Veveri 97, 602 00 Brno, Czech Republic
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31
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HASEGAWA Y, MATSUMOTO H, ISHII K. Development of the Microchip Isoelectric Focusing System with Fluorescence Correlation Spectroscopic Measurement. BUNSEKI KAGAKU 2011. [DOI: 10.2116/bunsekikagaku.60.977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Yutaka HASEGAWA
- The Graduate School for Creation of New Photonics Industries
- Electron Tube Devision, Hamamatsu Photonics K.K
| | | | - Katsuhiro ISHII
- The Graduate School for Creation of New Photonics Industries
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32
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Zhu Z, Ravelet C, Perrier S, Guieu V, Roy B, Perigaud C, Peyrin E. Multiplexed detection of small analytes by structure-switching aptamer-based capillary electrophoresis. Anal Chem 2010; 82:4613-20. [PMID: 20446673 DOI: 10.1021/ac100755q] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Affinity probe capillary electrophoresis (APCE) assays, combining the separation power of CE with the specificity of interactions occurring between a target and a molecular recognition element (MRE), have become important analytical tools in many application fields. In this report, a rationalized strategy, derived from the structure-switching aptamer concept, is described for the design of a novel APCE mode dedicated to small molecule detection. Two assay configurations were reported. The first one, developed for the single-analyte determination, was based on the use of a cholesteryl-tagged aptamer (Chol-Apt) as the MRE and its fluorescein-labeled complementary strand (CS*) as the tracer (laser-induced fluorescence detection). Under micellar electrokinetic chromatography (MEKC) conditions, free CS* and the hybrid formed with Chol-Apt (duplex*) were efficiently separated (and then quantified) through the specific shift of the electrophoretic mobility of the cholesteryl-tagged species in the presence of a neutral micellar phase. When the target was introduced into the preincubated sample, the hybridized form was destabilized, resulting in a decrease in the duplex* peak area and a concomitant increase in the free CS* peak area. The second format, especially designed for multianalyte sensing, employed dually cholesteryl- and fluorescein-labeled complementary strands (Chol-CS*) of different lengths and unmodified aptamers (Apt). The size-dependent electrophoretic separation of different Chol-CS* forms from each other and from their corresponding duplexes* was also accomplished under MEKC conditions. The simultaneous detection of multiple analytes in a single capillary was performed by monitoring accurately each target-induced duplex-to-complex change. This method could expand significantly the potential of small solute APCE analysis in terms of simplicity, adaptability, generalizability, and high-throughput analysis capability.
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Affiliation(s)
- Zhenyu Zhu
- Departement de Pharmacochimie Moléculaire, UMR 5063 CNRS, ICMG FR 2607, Université Grenoble I, Campus universitaire, Saint-Martin d'Hères, France
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33
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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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34
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El-Hady D, Kühne S, El-Maali N, Wätzig H. Precision in affinity capillary electrophoresis for drug–protein binding studies. J Pharm Biomed Anal 2010; 52:232-41. [DOI: 10.1016/j.jpba.2009.12.022] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2009] [Revised: 12/14/2009] [Accepted: 12/18/2009] [Indexed: 11/25/2022]
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35
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Klepárník K, Boček P. Electrophoresis today and tomorrow: Helping biologists' dreams come true. Bioessays 2010; 32:218-226. [PMID: 20127703 DOI: 10.1002/bies.200900152] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Intensive research and development of electrophoresis methodology and instrumentation during past decades has resulted in unique methods widely implemented in bioanalysis. While two-dimensional electrophoresis and denaturing polyacrylamide gel electrophoresis in sodium dodecylsulfate are still the most frequently used electrophoretic methods applied to analyses of proteins, new miniaturized capillary and microfluidic versions of electromigrational methods have been developed. High-throughput electrophoretic instruments with hundreds of capillaries for parallel separations and laser-induced fluorescence detection of labeled DNA strands have been of key importance for the scientific and commercial success of the Human Genome Project. Another powerful method, capillary isoelectric focusing with pressurized and pH-driven mobilization, provides efficient separations and on-line sensitive detection of proteins, bacteria and viruses. Electrophoretic microfluidic devices can integrate single-cell injection, cell lysis, separation of its components and fluorescence or mass spectrometry detection. These miniaturized devices also proved the capability of single-molecule detection.
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Affiliation(s)
- Karel Klepárník
- Institute of Analytical Chemistry, Academy of Sciences of the Czech Republic, Veveří 97, CZ-602 00 Brno, Czech Republic
| | - Petr Boček
- Institute of Analytical Chemistry, Academy of Sciences of the Czech Republic, Veveří 97, CZ-602 00 Brno, Czech Republic
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Wang C, Li T, Wang Z, Feng F, Wang H. Quantitative study of stereospecific binding of monoclonal antibody to anti-benzo(a)pyrene diol epoxide-N2-dG adducts by capillary electrophoresis immunoassay. J Chromatogr A 2010; 1217:2254-61. [DOI: 10.1016/j.chroma.2010.02.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2009] [Revised: 02/03/2010] [Accepted: 02/12/2010] [Indexed: 10/19/2022]
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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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Moser AC, Hage DS. Capillary electrophoresis-based immunoassays: principles and quantitative applications. Electrophoresis 2008; 29:3279-95. [PMID: 18646279 DOI: 10.1002/elps.200700871] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The use of CE as a tool to conduct immunoassays has been an area of increasing interest over the last decade. This approach combines the efficiency, small sample requirements, and relatively high speed of CE with the selectivity of antibodies as binding agents. This review examines the various assay formats and detection modes that have been reported for these assays, along with some representative applications. Most CE immunoassays in the past have employed homogeneous methods in which the sample and reagents are allowed to react in solution. These homogeneous methods have been conducted as both competitive binding immunoassays and as noncompetitive binding immunoassays. Fluorescent labels are most commonly used for detection in these assays, but enzyme labels have also been utilized for such work. Some additional work has been performed in CE immunoassays with heterogeneous methods in which either antibodies or an analog of the analyte is immobilized to a solid support. These heterogeneous methods can be used for the selective isolation of analytes prior to their separation by CE or to remove a given species from a sample/reagent mixture prior to analysis by CE. These CE immunoassays can be used with a variety of detection modes, such as fluorescence, UV/Vis absorbance, chemiluminescence, electrochemical measurements, MS, and surface plasmon resonance.
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Affiliation(s)
- Annette C Moser
- Chemistry Department, University of Nebraska, Kearney, NE, USA
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Meagher RJ, Hatch AV, Renzi RF, Singh AK. An integrated microfluidic platform for sensitive and rapid detection of biological toxins. LAB ON A CHIP 2008; 8:2046-53. [PMID: 19023467 DOI: 10.1039/b815152k] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Towards designing a portable diagnostic device for detecting biological toxins in bodily fluids, we have developed microfluidic chip-based immunoassays that are rapid (< 20 minutes), require minimal sample volume (<10 microL) and have appreciable sensitivity and dynamic range (microM-pM). The microfluidic chip is being integrated with miniaturized electronics, optical elements, fluid-handling components, and data acquisition software to develop a portable, self-contained device. The device is intended for rapid, point-of-care (and, in future, point-of-incident) testing in case of an accidental or intentional exposure/intoxication to biotoxins. Detection of toxins and potential host-response markers is performed using microfluidic electrophoretic immunoassays integrated with sample preconcentration and mixing of analytes with fluorescently labeled antibodies. Preconcentration is enabled by photopolymerizing a thin, nanoporous membrane with a MW cut-off of approximately 10 kDa in the sample loading region of the chip. Polymeric gels with larger pores are located adjacent to the size exclusion membrane to perform electrophoretic separation of antibody-analyte complex and excess antibody. Measurement of the ratio of bound and unbound immune-complex using sensitive laser-induced fluorescence detection provides quantitation of analyte in the sample. We have demonstrated electrophoretic immunoassays for the biotoxins ricin, Shiga toxin I, and Staphylococcal enterotoxin B (SEB). With off-chip mixing and no sample preconcentration, the limits of detection (LOD) were 300 pM for SEB, 500 pM for Shiga toxin I, and 20 nM for ricin. With a 10 min on-chip preconcentration, the LOD for SEB is <10 pM. The portable device being developed is readily applicable to detection of proteinaceous biomarkers of many other diseases and is intended to represent the next-generation diagnostic devices capable of rapid and quantitative measurements of multiple analytes simultaneously.
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Analysis of proteins in solution using affinity capillary electrophoresis. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2008. [PMID: 18826064 DOI: 10.1007/978-1-59745-582-4_21] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register]
Abstract
Analysis of protein interactions by means of capillary electrophoresis (CE) has unique challenges and rewards. The choice of analysis conditions, especially involving electrophoresis buffers, are crucial and not universal for protein analysis. If conditions for analysis can be worked out, it is possible to utilize CE quantitatively and qualitatively to characterize protein-ligand binding involving unmodified molecules in solution and taking place under physiological conditions. This chapter deals with the most important practical considerations in capillary electrophoretic affinity approaches, affinity CE (ACE). The text emphasizes the most critical factors for successful analyses and has application examples illustrating various types of information offered by ACE-based studies. Also included are step-by-step accounts of the two main classes of experimental design: the pre-equilibration ACE (in the form of CE-frontal analysis (CE-FA)) and mobility shift ACE together with examples of their use. The ACE approaches for binding assays of proteins should be considered when the biological material is scarce, when any kind of labeling is not possible or desired, when the interacting molecules are the same size and when rapid and simple method development is a priority.
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Reichmuth DS, Wang SK, Barrett LM, Throckmorton DJ, Einfeld W, Singh AK. Rapid microchip-based electrophoretic immunoassays for the detection of swine influenza virus. LAB ON A CHIP 2008; 8:1319-1324. [PMID: 18651074 DOI: 10.1039/b801396a] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Towards developing rapid and portable diagnostics for detecting zoonotic diseases, we have developed microchip-based electrophoretic immunoassays for sensitive and rapid detection of viruses. Two types of microchip-based electrophoretic immunoassays were developed. The initial assay used open channel electrophoresis and laser-induced fluorescence detection with a labeled antibody to detect influenza virus. However, this assay did not have adequate sensitivity to detect viruses at relevant concentrations for diagnostic applications. Hence, a novel assay was developed that allows simultaneous concentration and detection of viruses using a microfluidic chip with an integrated nanoporous membrane. The size-exclusion properties of the in situ polymerized polyacrylamide membrane are exploited to simultaneously concentrate viral particles and separate the virus/fluorescent antibody complex from the unbound antibody. The assay is performed in two simple steps--addition of fluorescently labeled antibodies to the sample, followed by concentration of antibody-virus complexes on a porous membrane. Excess antibodies are removed by electrophoresis through the membrane and the complex is then detected downstream of the membrane. This new assay detected inactivated swine influenza virus at a concentration four times lower than that of the open-channel electrophoresis assay. The total assay time, including device regeneration, is six minutes and requires <50 microl of sample. The filtration effect of the polymer membrane eliminates the need for washing, commonly required with surface-based immunoassays, increasing the speed of the assay. This assay is intended to form the core of a portable device for the diagnosis of high-consequence animal pathogens such as foot-and-mouth disease. The electrophoretic immunoassay format is rapid and simple while providing the necessary sensitivity for diagnosis of the illness state. This would allow the development of a portable, cost-effective, on-site diagnostic system for rapid screening of large populations of livestock, including sheep, pigs, cattle, and potentially birds.
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Affiliation(s)
- David S Reichmuth
- Sandia National Laboratories, Chemical and Radiation Detection Laboratories, P.O. Box 969, Livermore, CA 94551, USA.
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Yang P, Kennedy RT. High performance liquid chromatography coupled on-line to capillary electrophoresis with laser-induced fluorescence detection for detecting inhibitors of Src homology 2 domain–phosphopeptide binding in mixtures. J Chromatogr A 2008; 1194:225-30. [DOI: 10.1016/j.chroma.2008.04.072] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2007] [Revised: 04/08/2008] [Accepted: 04/17/2008] [Indexed: 10/22/2022]
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Wang Q, Luo G, Wang Y, Yeung WS. Capillary Electrophoresis Based Immunoassay for Monoclonal Antibody with Diode Laser Induced Fluorescence Detection. ANAL LETT 2008. [DOI: 10.1080/00032710008543076] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Hubbuch J, Kula MR. Confocal laser scanning microscopy as an analytical tool in chromatographic research. Bioprocess Biosyst Eng 2008; 31:241-59. [DOI: 10.1007/s00449-008-0197-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2007] [Accepted: 01/02/2008] [Indexed: 11/29/2022]
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45
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Sumitomo K, Yamaguchi Y. High performance RNA separation by in-capillary denaturing gel electrophoresis with carboxylic acid as RNA denaturant. ACTA ACUST UNITED AC 2008. [DOI: 10.2198/sbk.52.133] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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46
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Zhang S, Li X, Zhang F. CE-based simultaneous liquid-phase noncompetitive enzyme immunoassay for three tumor markers in human serum using electrochemical detection. Electrophoresis 2007; 28:4427-34. [DOI: 10.1002/elps.200700026] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Knittle JE, Roach D, Vander Horn PB, Voss KO. Laser-Induced Fluorescence Detector for Capillary-Based Isoelectric Immunoblot Assay. Anal Chem 2007; 79:9478-83. [DOI: 10.1021/ac071537z] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- James E. Knittle
- Cell Biosciences, Inc., 1050 Page Mill Road, Palo Alto, California 94304
| | - David Roach
- Cell Biosciences, Inc., 1050 Page Mill Road, Palo Alto, California 94304
| | | | - Karl O. Voss
- Cell Biosciences, Inc., 1050 Page Mill Road, Palo Alto, California 94304
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Abstract
The high affinity and specificity of aptamers make them ideal reagents for a wide range of analytical applications. It is not surprising that they are finding application in microfluidics as well. CE has proven to be an efficient technique for isolating aptamers. Aptamers have been used as affinity reagents in CE assays. Aptamer-based chromatography stationary phases have demonstrated unique selectivities. Possibly the application that holds the highest potential is aptamer microarrays for screening proteomic samples.
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Herr AE, Hatch AV, Giannobile WV, Throckmorton DJ, Tran HM, Brennan JS, Singh AK. Integrated microfluidic platform for oral diagnostics. Ann N Y Acad Sci 2007; 1098:362-74. [PMID: 17435142 PMCID: PMC2572166 DOI: 10.1196/annals.1384.004] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
While many point-of-care (POC) diagnostic methods have been developed for blood-borne analytes, development of saliva-based POC diagnostics is in its infancy. We have developed a portable microfluidic device for detection of potential biomarkers of periodontal disease in saliva. The device performs rapid microfluidic chip-based immunoassays (<3-10 min) with low sample volume requirements (10 microL) and appreciable sensitivity (nM-pM). Our microfluidic method facilitates hands-free saliva analysis by integrating sample pretreatment (filtering, enrichment, mixing) with electrophoretic immunoassays to quickly measure analyte concentrations in minimally pretreated saliva samples. The microfluidic chip has been integrated with miniaturized electronics, optical elements, such as diode lasers, fluid-handling components, and data acquisition software to develop a portable, self-contained device. The device and methods are being tested by detecting potential biomarkers in saliva samples from patients diagnosed with periodontal disease. Our microchip-based analysis can readily be extended to detection of biomarkers of other diseases, both oral and systemic, in saliva and other oral fluids.
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Affiliation(s)
- Amy E Herr
- Biosystems Research Department, Sandia National Laboratories, Livermore, CA 94551-0969, USA
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50
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Storms SM, Feltus A, Barker AR. Verification and Implementation of the Pharmeuropa Method for Somatropin Charged Variants by CZE. Chromatographia 2007. [DOI: 10.1365/s10337-007-0217-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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