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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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2
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Beutner A, Herl T, Matysik FM. Selectivity enhancement in capillary electrophoresis by means of two-dimensional separation or dual detection concepts. Anal Chim Acta 2018; 1057:18-35. [PMID: 30832915 DOI: 10.1016/j.aca.2018.11.042] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 11/01/2018] [Accepted: 11/19/2018] [Indexed: 12/18/2022]
Abstract
For the identification and quantification of analytes in complex samples, highly selective analytical strategies are required. The selectivity of single separation techniques such as gas chromatography (GC), liquid chromatography (LC), or capillary electrophoresis (CE) with common detection principles can be enhanced by hyphenating orthogonal separation techniques but also by using complementary detection systems. In this review, two-dimensional systems containing CE in at least one dimension are reviewed, namely LC-CE or 2D CE systems. Particular attention is paid to the aspect of selectivity enhancement due to the orthogonality of the different separation mechanisms. As an alternative concept, dual detection approaches are reviewed using the common detectors of CE such as UV/VIS, laser-induced fluorescence, capacitively coupled contactless conductivity (C4D), electrochemical detection, and mass spectrometry. Special emphasis is given to dual detection systems implementing the highly flexible C4D as one detection component. Selectivity enhancement can be achieved in case of complementarity of the different detection techniques.
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Affiliation(s)
- Andrea Beutner
- Institute of Analytical Chemistry, Chemo- and Biosensors, University of Regensburg, Universitaetsstrasse 31, 93053, Regensburg, Germany
| | - Thomas Herl
- Institute of Analytical Chemistry, Chemo- and Biosensors, University of Regensburg, Universitaetsstrasse 31, 93053, Regensburg, Germany
| | - Frank-Michael Matysik
- Institute of Analytical Chemistry, Chemo- and Biosensors, University of Regensburg, Universitaetsstrasse 31, 93053, Regensburg, Germany.
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3
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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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4
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LI X, FU L, WENG Q, LI J. A Miniaturized Transverse Flow Gating Interface for the On-line Coupling of Solid-phase Extraction with Capillary Electrophoresis. ANAL SCI 2014; 30:1151-6. [DOI: 10.2116/analsci.30.1151] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Xintong LI
- Department of Chemistry, Liaoning Normal University
| | - Lianjuan FU
- Department of Chemistry, Liaoning Normal University
| | | | - Jinxiang LI
- Department of Chemistry, Liaoning Normal University
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5
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Jia M, Belyavskaya E, Deuster P, Sternberg EM. Development of a Sensitive Microarray Immunoassay for the Quantitative Analysis of Neuropeptide Y. Anal Chem 2012; 84:6508-14. [DOI: 10.1021/ac3014548] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Min Jia
- Section on Neuroendocrine Immunology & Behavior, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Elena Belyavskaya
- Section on Neuroendocrine Immunology & Behavior, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Patricia Deuster
- Department
of Military and Emergency Medicine, Uniformed Services University of the Health Sciences, Bethesda,
Maryland 20814, United States
| | - Esther M. Sternberg
- Section on Neuroendocrine Immunology & Behavior, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland 20892, United States
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Guillo C, Truong TM, Roper MG. Simultaneous capillary electrophoresis competitive immunoassay for insulin, glucagon, and islet amyloid polypeptide secretion from mouse islets of Langerhans. J Chromatogr A 2011; 1218:4059-64. [PMID: 21620410 DOI: 10.1016/j.chroma.2011.05.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Revised: 05/04/2011] [Accepted: 05/06/2011] [Indexed: 12/21/2022]
Abstract
A capillary electrophoresis competitive immunoassay was developed for the simultaneous quantitation of insulin, glucagon, and islet amyloid polypeptide (IAPP) secretion from islets of Langerhans. Separation buffers and conditions were optimized for the resolution of fluorescein isothiocyanate (FITC)-labeled glucagon and IAPP immunoassay reagents, which were excited with the 488 nm line of an Ar(+) laser and detected at 520 nm with a photomultiplier tube (PMT). Cy5-labeled insulin immunoassay reagents were excited by a 635 nm laser diode module and detected at 700 nm with a separate PMT. Optimum resolution was achieved with a 20mM carbonate separation buffer at pH 9.0 using a 20 cm effective separation length with an electric field of 500 V/cm. Limits of detection for insulin, glucagon, and IAPP were 2, 3, and 3 nM, respectively. This method was used to monitor the simultaneous secretion of these peptides from as few as 14 islets after incubation in 4, 11, and 20 mM glucose for 6h. For insulin and IAPP, a statistically significant increase in secretion levels was observed, while glucagon levels were significantly reduced in the 4 and 11 mM glucose conditions. To further demonstrate the utility of the assay, the Ca(2+)-dependent secretion of these peptides was demonstrated which agreed with published reports. The ability to examine the secretion of multiple peptides may allow for the determination of regulation of secretory processes within islets of Langerhans.
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Affiliation(s)
- Christelle Guillo
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306, USA
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Whim MD. Pancreatic beta cells synthesize neuropeptide Y and can rapidly release peptide co-transmitters. PLoS One 2011; 6:e19478. [PMID: 21559341 PMCID: PMC3084883 DOI: 10.1371/journal.pone.0019478] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2010] [Accepted: 04/07/2011] [Indexed: 01/09/2023] Open
Abstract
Background In addition to polypeptide hormones, pancreatic endocrine cells synthesize a variety of bioactive molecules including classical transmitters and neuropeptides. While these co-transmitters are thought to play a role in regulating hormone release little is known about how their secretion is regulated. Here I investigate the synthesis and release of neuropeptide Y from pancreatic beta cells. Methodology/Principal Findings NPY appears to be an authentic co-transmitter in neonatal, but not adult, beta cells because (1) early in mouse post-natal development, many beta cells are NPY-immunoreactive whereas no staining is observed in beta cells from NPY knockout mice; (2) GFP-expressing islet cells from an NPY(GFP) transgenic mouse are insulin-ir; (3) single cell RT-PCR experiments confirm that the NPY(GFP) cells contain insulin mRNA, a marker of beta cells. The NPY-immunoreactivity previously reported in alpha and delta cells is therefore likely to be due to the presence of NPY-related peptides. INS-1 cells, a beta cell line, are also NPY-ir and contain NPY mRNA. Using the FMRFamide tagging technique, NPY secretion was monitored from INS-1 beta cells with high temporal resolution. Peptide release was evoked by brief depolarizations and was potentiated by activators of adenylate cyclase and protein kinase A. Following a transient depolarization, NPY-containing dense core granules fused with the cell membrane and discharged their contents within a few milliseconds. Conclusions These results indicate that after birth, NPY expression in pancreatic islets is restricted to neonatal beta cells. The presence of NPY suggests that peptide co-transmitters could mediate rapid paracrine or autocrine signaling within the endocrine pancreas. The FMRFamide tagging technique may be useful in studying the release of other putative islet co-transmitters in real time.
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Affiliation(s)
- Matthew D Whim
- Department of Cell Biology and Anatomy, Louisiana State University Health Sciences Center, New Orleans, Louisiana, United States of America.
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Opekar F, Coufal P, Štulík K. Rapid Capillary Zone Electrophoresis Along Short Separation Pathways and Its Use in Some Hyphenated Systems: A Critical Review. Chem Rev 2009; 109:4487-99. [DOI: 10.1021/cr900018r] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- František Opekar
- Charles University in Prague, Faculty of Science, Department of Analytical Chemistry, Albertov 2030, CZ-128 43 Prague 2, Czech Republic
| | - Pavel Coufal
- Charles University in Prague, Faculty of Science, Department of Analytical Chemistry, Albertov 2030, CZ-128 43 Prague 2, Czech Republic
| | - Karel Štulík
- Charles University in Prague, Faculty of Science, Department of Analytical Chemistry, Albertov 2030, CZ-128 43 Prague 2, Czech Republic
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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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10
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Simpson SL, Quirino JP, Terabe S. On-line sample preconcentration in capillary electrophoresis. J Chromatogr A 2008; 1184:504-41. [DOI: 10.1016/j.chroma.2007.11.001] [Citation(s) in RCA: 269] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2007] [Revised: 10/30/2007] [Accepted: 11/01/2007] [Indexed: 02/06/2023]
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11
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Tempels FWA, Underberg WJM, Somsen GW, de Jong GJ. Design and applications of coupled SPE-CE. Electrophoresis 2008; 29:108-28. [DOI: 10.1002/elps.200700149] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Phillips TM, Wellner EF. Measurement of naproxen in human plasma by chip-based immunoaffinity capillary electrophoresis. Biomed Chromatogr 2006; 20:662-7. [PMID: 16779772 DOI: 10.1002/bmc.673] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
An electrokinetic immunoassay performed in a chip-based capillary electrophoresis system is described for the rapid measurement of naproxen in human plasma. The system employs a fluorescently labeled antibody to capture and detect the analyte of interest within a 5 min total assay time with an LOD of 0.025 microg/mL and a saturation level of 450 microg/mL. The system compared well with a conventional HPLC technique but was found to be much faster. Application of the electrokinetic assay to the study of patients with allergy to naproxen demonstrated increased concentrations of the drug extending past the predicted elimination half-life. The portability of the system and its ability to process up to 18 samples per hour makes it suitable for use in emergency room situations.
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Affiliation(s)
- Terry M Phillips
- Ultramicro Analytical Immunochemistry Resource, Division of Bioengineering and Physical Science, Office of Research Services, National Institutes of Health, Bethesda, MD 20892, USA.
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Phillips TM, Wellner E. Measurement of neuropeptides in clinical samples using chip-based immunoaffinity capillary electrophoresis. J Chromatogr A 2006; 1111:106-11. [PMID: 16472819 DOI: 10.1016/j.chroma.2006.01.102] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2005] [Revised: 01/23/2006] [Accepted: 01/24/2006] [Indexed: 11/30/2022]
Abstract
The current interest in micro-fabrication has extended to the clinical arena where there is a growing lobby for promoting these for point-of-care purposes. The advantages of such devices are their relative speed of analysis, lower reagent costs, and their application to clinical screening and diagnosis. Two chip-based capillary electrophoresis systems have been designed and their performance evaluated for rapidly measuring the concentrations of inflammatory neuropeptides in tissue fluids of patients with neuropeptide-associated muscle pain. Both chips were manufactured to fit a commercially available chip electrophoresis system. One chip was designed to perform electrokinetic flow immunoassays while the other utilized an immunoaffinity port, containing an array of immobilized antibodies, to capture the analytes of interest. Comparison of the results to commercially available high-sensitivity immunoassays demonstrated that both chip-based systems could provide a relatively fast, accurate procedure for studying inflammatory biomarkers in complex biological fluids. However, the immunoaffinity capture system proved the superior of the two chips. Using this system, twelve different inflammation-associated mediators could be determined in approximately 2 min as compared to 30 min when using the flow immunoassay chip. With the ever-expanding array of antibodies that are commercially available, this chip-based system can be applied to a wide variety of different analyses.
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Affiliation(s)
- Terry M Phillips
- Ultramicro Analytical Immunochemistry Resource, Division of Bioengineering and Physical Science, National Institutes of Health, Bethesda, MD 20892, USA.
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14
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Lacroix M, Poinsot V, Fournier C, Couderc F. Laser-induced fluorescence detection schemes for the analysis of proteins and peptides using capillary electrophoresis. Electrophoresis 2005; 26:2608-21. [PMID: 15948219 DOI: 10.1002/elps.200410414] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Over the past few years, a large number of studies have been prepared that describe the analysis of peptides and proteins using capillary electrophoresis (CE) and laser-induced fluorescence (LIF). These studies have focused on two general goals: (i) development of automatic, selective and quick separation and detection of mixtures of peptides or proteins; (ii) generation of new methods of quantitation for very low concentrations (nm and subnanomolar) of peptides. These two goals are attained with the use of covalent labelling reactions using a variety of dyes that can be readily excited by the radiation from a commonly available laser or via the use of noncovalent labelling (immunoassay using a labelled antibody or antigen or noncovalent dye interactions). In this review article, we summarize the works which were performed for protein and peptide analysis via CE-LIF.
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Affiliation(s)
- Marlene Lacroix
- Laboratoire des IMRCP, UMR 5623, ERT 1046, Université Paul Sabatier, Toulouse, France
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15
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Meng R, Xia W, Sandberg M, Stephens R, Weber SG. Online preconcentration of thyrotropin-releasing hormone (TRH) by SDS-modified reversed phase column for microbore and capillary high-performance liquid chromatography (HPLC). J Chromatogr A 2005; 1071:179-84. [PMID: 15865191 DOI: 10.1016/j.chroma.2004.12.032] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Thyrotropin-releasing hormone (TRH, pGlu-His-Pro-amide) is an important tripeptide existing in biological systems at low concentrations. It is a fairly hydrophilic peptide, cationic in acidic solutions. Preconcentration online before reversed phase chromatography separation can enhance concentration detection limits of hydrophobic, but not hydrophilic species. The hydrophilic TRH can be preconcentrated using a reversed phase precolumn charged with sodium dodecyl sulfate (SDS). The separation also uses SDS. The preconcentration is effective for a microbore system, achieving detection limit of 250 pM for a sample size of 500 microl with electrochemical detection of the biuret complex formed post column. Preconcentration using an online precolumn is also effective in packed capillary high-performance liquid chromatography (HPLC) with a detection limit of 3 nM in 24 microl.
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Affiliation(s)
- Rong Meng
- Department of Chemistry, University of Pittsburgh, 603 Chevron Science Center, 219 Parkman Drive, Pittsburgh, PA 15260, USA
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Fluorescence detection in capillary electrophoresis. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/s0166-526x(05)45006-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Bergström SK, Samskog J, Markides KE. Development of a poly(dimethylsiloxane) interface for on-line capillary column liquid chromatography-capillary electrophoresis coupled to sheathless electrospray ionization time-of-flight mass spectrometry. Anal Chem 2004; 75:5461-7. [PMID: 14710825 DOI: 10.1021/ac030117g] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
An interface in elastomeric poly(dimethylsiloxane) (PDMS) for on-line orthogonal coupling of packed capillary liquid chromatography (LC) (i.d. = 0.2 mm) with capillary electrophoresis (CE) in combination with sheathless electrospray ionization (ESI) time-of-flight mass spectrometric (TOFMS) detection is presented. The new interface has a two-level design, which in combination with a continuous CE electrolyte flow through the interface provides integrity of the LC effluent and the CE separation until an injection is desired. The transparent and flexible PDMS material was found to have a number of advantages when combined with fused silica column technology, including ease to follow the process and ease to exchange columns. By combining conventional microscale systems of LC, CE, and ESI-MS, respectively, the time scales of the individual dimensions were harmonized for optimal peak capacity per unit time. The performance of the LC-CE-TOFMS system was evaluated using peptides as model substances. A S/N of about 330 was achieved for leucine-enkephaline from a 0.5 microL LC injection of 25 microg/mL peptide standard.
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Affiliation(s)
- Sara K Bergström
- Department of Analytical Chemistry, Uppsala University, P.O. Box 599, SE-751 24 Uppsala, Sweden
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Yeung WSB, Luo GA, Wang QG, Ou JP. Capillary electrophoresis-based immunoassay. J Chromatogr B Analyt Technol Biomed Life Sci 2004; 797:217-28. [PMID: 14630151 DOI: 10.1016/s1570-0232(03)00489-6] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Capillary electrophoresis-based immunoassay (CEIA) is a developing analytical technique with a number of advantages over conventional immunoassay, such as reduced sample consumption, simpler procedure, easy simultaneous determination of multiple analytes, and short analysis time. However, there are still a number of technical issues that researchers on CEIA have to solve before the assay can be more widely used. These issues include method to improve the concentration sensitivity of the assay, requirement for robust separation strategy for different analytes, and method to increase the throughput of the assay. The approaches to solve these issues are reviewed. Several studies have been devoted to develop general separation strategies for CEIA, and to enhance the sensitivity of detection. The recent development of microchip-based CEIA is encouraging and is likely to address more drawbacks of CEIA, particularly on the throughput issue.
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Affiliation(s)
- W S B Yeung
- Department of Obstetrics and Gynaecology, The University of Hong Kong, Queen Mary Hospital, Pokfulam Road, Hong Kong, PR China.
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19
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Immunoassays using capillary electrophoresis laser induced fluorescence detection for DNA adducts. Anal Chim Acta 2003. [DOI: 10.1016/s0003-2670(03)00631-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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20
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Abstract
Because immunoassay responds to epitopes, and many molecules share the same peptide epitope, it is very difficult to obtain an accurate understanding of peptides, their creation and hydrolysis, in biological systems. Separate-and-detect approaches have merit in that the many active peptides and inactive fragments of a particular system can be separately determined. This review discusses the separation, by chromatography and capillary electrophoresis, and detection, by absorbance, fluorescence, electrochemistry, and immunoassay techniques. When separation pre-concentration is accompanied by laser-induced fluorescence or biuret-based electrochemical detection, nM-pM detection limits are obtained.
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Affiliation(s)
- Mats Sandberg
- Department of Cell Biology, University of Gothenburg, Gothenburg, Sweden
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