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Caslavska J, Schild C, Thormann W. High-resolution capillary zone electrophoresis and mass spectrometry for distinction of undersialylated and hypoglycosylated transferrin glycoforms in body fluids. J Sep Sci 2019; 43:241-257. [PMID: 31605446 DOI: 10.1002/jssc.201900857] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 10/01/2019] [Accepted: 10/09/2019] [Indexed: 12/21/2022]
Abstract
High-resolution capillary zone electrophoresis is used to distinguish transferrin glycoforms present in human serum, cerebrospinal fluid, and serum treated with neuraminidase and N-glycosidase F. The obtained data are compared to mass spectrometry data from the literature. The main focus is on the analysis of the various asialo-transferrin, monosialo-transferrin, and disialo-transferrin molecules found in these samples. The features of capillary zone electrophoresis and mass spectrometry are reviewed and highlighted in the context of the analysis of undersialylated and hypoglycosylated transferrin molecules. High-resolution capillary zone electrophoresis represents an effective tool to assess the diversity of transferrin patterns whereas mass spectrometry is the method of choice to elucidate structural identification about the glycoforms. Hypoglycosylated transferrin glycoforms present in sera of alcohol abusers and normal subjects are structurally identical to those in sera of patients with a congenital disorder of glycosylation type I. Asialo-transferrin, monosialo-transferrin and disialo-transferrin observed in sera of patients with a type II congenital disorder of glycosylation or a hemolytic uremic syndrome, in cerebrospinal fluid and after treatment of serum with neuraminidase are undersialylated transferrin glycoforms with two N-glycans of varying structure. Undersialylated disialo-transferrin is also observed in sera with high levels of trisialo-transferrin.
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Affiliation(s)
- Jitka Caslavska
- Clinical Pharmacology Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Christof Schild
- Institute of Clinical Chemistry, Inselspital, University Hospital and University of Bern, Bern, Switzerland
| | - Wolfgang Thormann
- Clinical Pharmacology Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
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2
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Tobler M, Caslavska J, Burda P, Thormann W. High-resolution capillary zone electrophoresis for transferrin glycoform analysis associated with congenital disorders of glycosylation. J Sep Sci 2018; 41:2808-2818. [PMID: 29701302 DOI: 10.1002/jssc.201800082] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 04/18/2018] [Accepted: 04/19/2018] [Indexed: 11/10/2022]
Abstract
High-resolution capillary zone electrophoresis is used to assess the transferrin profile in serum of patients with eight different congenital disorders of glycosylation that represent type I, type II, and mixed type I/II disorders. Capillary zone electrophoresis data are compared to patterns obtained by gel isoelectric focusing. The high-resolution capillary zone electrophoresis method is shown to represent an effective tool to assess the diversity of transferrin patterns. Hypoglycosylated disialo-, monosialo-, and asialo-transferrin in type I cases can be distinguished from the corresponding underdesialylated transferrin glycoforms present in type II disorders. The latter can be separated from and detected ahead of their corresponding hypoglycosylated forms of type I patients. Both types of glycoforms are detected in sera of mixed type I/II patients. The assay has the potential to be used as screening method for congenital disorders of glycosylation. It can be run with a few microliters of serum when microvials are used.
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Affiliation(s)
- Micha Tobler
- Division of Metabolism, University Children's Hospital Zürich, Zürich, Switzerland
| | - Jitka Caslavska
- Clinical Pharmacology Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Patricie Burda
- Division of Metabolism, University Children's Hospital Zürich, Zürich, Switzerland
| | - Wolfgang Thormann
- Clinical Pharmacology Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
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3
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Caslavska J, Thormann W. Monitoring of transferrin isoforms in biological samples by capillary electrophoresis. J Sep Sci 2017; 41:303-322. [PMID: 28885776 DOI: 10.1002/jssc.201700914] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 09/04/2017] [Accepted: 09/04/2017] [Indexed: 11/10/2022]
Abstract
Work dealing with the monitoring of transferrin isoforms in human serum and other body fluids by capillary electrophoresis is reviewed. It comprises capillary zone electrophoresis and capillary isoelectric focusing efforts that led to the exploration and use of assays for the determination of carbohydrate-deficient transferrin as a marker for excessive alcohol intake, genetic variants of transferrin, congenital disorders of glycosylation and β-2-transferrin, which is a marker for cerebrospinal fluid leakage. This paper provides insight into the development, specifications, strengths, weaknesses, and routine use of the currently known capillary electrophoresis based assays suitable to detect transferrin isoforms in body fluids. The achievements reached so far indicate that capillary zone electrophoresis is an attractive technology to monitor the molecular forms of transferrin in biological specimens as the assays do not require an elaborate sample pretreatment and thus can be fully automated for high-throughput analyses on multicapillary instruments. Assays based on capillary isoelectric focusing are less attractive. They require immunoextraction of transferrin from the biological matrix and mobilization after focusing if instrumentation with a whole-column imaging detector is not available. Interactions of the carrier ampholytes with the iron of transferrin may prevent iron saturation and thus provide more complicated isoform patterns.
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Affiliation(s)
- Jitka Caslavska
- Clinical Pharmacology Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Wolfgang Thormann
- Clinical Pharmacology Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
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Nowak PM, Woźniakiewicz M, Gładysz M, Janus M, Kościelniak P. Improving repeatability of capillary electrophoresis-a critical comparison of ten different capillary inner surfaces and three criteria of peak identification. Anal Bioanal Chem 2017; 409:4383-4393. [PMID: 28484810 PMCID: PMC5486911 DOI: 10.1007/s00216-017-0382-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 04/18/2017] [Accepted: 04/25/2017] [Indexed: 01/30/2023]
Abstract
A poor repeatability of migration times caused by the fluctuations of electroosmotic flow (EOF) is an inherent weakness of capillary electrophoresis. Most researchers endeavor to prevent this problem using relative migration times or various capillary coatings which are expensive and not easy in comparison. Herein, we present an original approach to this problem: we apply a model sample designed to induce significant EOF instability, in order to critically compare ten capillary types with different physicochemical characteristics. Moreover, we accompany capillary modification with the evaluation of various criteria of peak identification: migration time, migration times ratio, and electrophoretic mobility. Our results show a great effectiveness of a dynamic coating in the stabilization of migration times, with the average RSD(%) value reduced from 3.5% (bare silica capillary) down to 0.5%. The good outcomes were also obtained for the surfactant-modified silica and amine capillaries. For the capillaries exhibiting significant instability of EOF, electrophoretic mobility turned out to be a more universal and reliable criterion of peak identification than relative migration time. It can be explained by an intrinsic dependency of migration times ratio on EOF change, which should always be considered during the selection of an internal standard.
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Affiliation(s)
- Paweł Mateusz Nowak
- Faculty of Chemistry, Department of Analytical Chemistry, Jagiellonian University in Kraków, Ingardena St. 3, 30-060, Kraków, Poland.
| | - Michał Woźniakiewicz
- Faculty of Chemistry, Department of Analytical Chemistry, Jagiellonian University in Kraków, Ingardena St. 3, 30-060, Kraków, Poland
| | - Marta Gładysz
- Faculty of Chemistry, Department of Analytical Chemistry, Jagiellonian University in Kraków, Ingardena St. 3, 30-060, Kraków, Poland
| | - Magdalena Janus
- Faculty of Chemistry, Department of Analytical Chemistry, Jagiellonian University in Kraków, Ingardena St. 3, 30-060, Kraków, Poland
| | - Paweł Kościelniak
- Faculty of Chemistry, Department of Analytical Chemistry, Jagiellonian University in Kraków, Ingardena St. 3, 30-060, Kraków, Poland
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5
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Hajba L, Guttman A. Recent advances in column coatings for capillary electrophoresis of proteins. Trends Analyt Chem 2017. [DOI: 10.1016/j.trac.2017.02.013] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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6
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Caslavska J, Lanz C, Burda P, Tobler M, Thormann W. Analysis of genetic variants of transferrin in human serum after desialylation by capillary zone electrophoresis and capillary isoelectric focusing. J Sep Sci 2017; 40:2488-2497. [PMID: 28371325 DOI: 10.1002/jssc.201700211] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 03/21/2017] [Accepted: 03/21/2017] [Indexed: 12/31/2022]
Abstract
Capillary electrophoresis analysis of transferrin in human serum is used to assess genetic variants after desialylation with neuraminidase and iron saturation to reduce the complexity of the transferrin pattern and thus facilitate the recognition of transferrin polymorphisms. Asialo-transferrin forms are analyzed by capillary zone electrophoresis using assay conditions as for the monitoring of carbohydrate-deficient transferrin or by capillary isoelectric focusing in a pH 5-8 gradient which requires immunoextraction of transferrin prior to analysis. With the carrier ampholytes used, peaks for iron saturated and iron depleted transferrin are monitored which indicates complexation of iron ions by carrier ampholytes. For BC, CD, and BD genetic variants, the expected peaks for B, C, and D forms of transferrin were detected with both methods. Monitoring of CC patterns revealed three cases, namely those producing double peaks in both methods, a double peak in capillary isoelectric focusing only and a double peak in capillary zone electrophoresis only. For all samples analyzed, data obtained by capillary isoelectric focusing could be confirmed with gel isoelectric focusing. The two capillary electrophoresis methods are shown to represent effective tools to assess unusual transferrin patterns, including genetic variants with dissimilar abundances of the two forms.
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Affiliation(s)
- Jitka Caslavska
- Clinical Pharmacology Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Christian Lanz
- Clinical Pharmacology Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Patricie Burda
- Division of Metabolism, University Children's Hospital Zürich, Zürich, Switzerland
| | - Micha Tobler
- Division of Metabolism, University Children's Hospital Zürich, Zürich, Switzerland
| | - Wolfgang Thormann
- Clinical Pharmacology Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
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Nowak PM, Woźniakiewicz M, Michalik M, Fiedor L, Kościelniak P. Capillary coating as an important factor in optimization of the off-line and on-line MEKC assays of the highly hydrophobic enzyme chlorophyllase. Anal Bioanal Chem 2017; 409:1493-1501. [PMID: 27888314 PMCID: PMC5306352 DOI: 10.1007/s00216-016-0097-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2016] [Revised: 11/07/2016] [Accepted: 11/11/2016] [Indexed: 12/15/2022]
Abstract
The choice between bare and coated capillaries is a key decision in the development and use of any methods based on capillary electrophoresis. In this work several permanently and dynamically coated capillaries were successfully implemented in a previously developed micellar electrokinetic chromatography (MEKC) assay of the plant membrane enzyme chlorophyllase. The results obtained demonstrate the rationale behind the use of capillary coating, which is crucial for successful optimization of both the off-line mode and the on-line/electrophoretically mediated microanalysis assay mode. The application of an amine permanently coated capillary (eCAP) is a simple way to significantly increase the repeatability of migration times and peak areas, and to ensure a strong electroosmotic flow that considerably decreases the overall analysis time. A dynamic coating (CEofix) allows one to apply an on-line incubation to control the reaction progress inside the capillary, and to increase the signal-to-noise ratio and peak efficiency. The dynamic coating is possible with use of both the normally applied uncoated silica capillary and the precoated amine capillary, which ensures more repeatable migration times. The strong points of the uncoated silica capillary are its attractive price and wide range of pH that can be applied. The characteristics presented may simplify the choice of capillary modification, especially in the case of hydrophobic analytes, MEKC-based separations, and other enzymatic assays.
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Affiliation(s)
- Paweł Mateusz Nowak
- Faculty of Chemistry, Jagiellonian University in Kraków, Ingardena 3, 30-060, Kraków, Poland.
| | - Michał Woźniakiewicz
- Faculty of Chemistry, Jagiellonian University in Kraków, Ingardena 3, 30-060, Kraków, Poland
| | - Maciej Michalik
- Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University in Kraków, Gronostajowa 7, 30-387, Kraków, Poland
| | - Leszek Fiedor
- Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University in Kraków, Gronostajowa 7, 30-387, Kraków, Poland
| | - Paweł Kościelniak
- Faculty of Chemistry, Jagiellonian University in Kraków, Ingardena 3, 30-060, Kraków, Poland
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8
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Nowak PM, Woźniakiewicz M, Garnysz M, Kościelniak P. A comparative study of various physicochemically modified capillaries used in CE technique for the three distinct analytical purposes. J Chromatogr B Analyt Technol Biomed Life Sci 2016; 1020:134-41. [DOI: 10.1016/j.jchromb.2016.03.037] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Revised: 03/19/2016] [Accepted: 03/24/2016] [Indexed: 10/22/2022]
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9
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Woolley T, Allen P, Fitzgerald L, Izzard L, Rutter E. Sebia Capillarys 2 versus the Helena Biosciences V8 capillary electrophoresis analyser for carbohydrate-deficient transferrin measurement: comparison and analytical evaluation. Br J Biomed Sci 2016; 72:23-7. [DOI: 10.1080/09674845.2015.11666791] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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10
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New insights in carbohydrate-deficient transferrin analysis with capillary electrophoresis–mass spectrometry. Forensic Sci Int 2014; 243:14-22. [DOI: 10.1016/j.forsciint.2014.03.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Revised: 01/21/2014] [Accepted: 03/12/2014] [Indexed: 11/21/2022]
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11
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Medina-Casanellas S, Benavente F, Giménez E, Barbosa J, Sanz-Nebot V. On-line immunoaffinity solid-phase extraction capillary electrophoresis mass spectrometry for the analysis of large biomolecules: A preliminary report. Electrophoresis 2014; 35:2130-6. [DOI: 10.1002/elps.201400119] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Revised: 03/10/2014] [Accepted: 04/05/2014] [Indexed: 11/08/2022]
Affiliation(s)
| | - Fernando Benavente
- Department of Analytical Chemistry; University of Barcelona; Barcelona Spain
| | - Estela Giménez
- Department of Analytical Chemistry; University of Barcelona; Barcelona Spain
| | - José Barbosa
- Department of Analytical Chemistry; University of Barcelona; Barcelona Spain
| | - Victoria Sanz-Nebot
- Department of Analytical Chemistry; University of Barcelona; Barcelona Spain
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12
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Caslavska J, Joneli J, Wanzenried U, Schiess J, Lanz C, Thormann W. Determination of genetic transferrin variants in human serum by high-resolution capillary zone electrophoresis†. J Sep Sci 2014; 37:1663-70. [DOI: 10.1002/jssc.201400243] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Revised: 04/08/2014] [Accepted: 04/08/2014] [Indexed: 12/17/2022]
Affiliation(s)
- Jitka Caslavska
- Clinical Pharmacology Laboratory; Institute for Infectious Diseases; University of Bern; Bern Switzerland
| | - Jeannine Joneli
- Clinical Pharmacology Laboratory; Institute for Infectious Diseases; University of Bern; Bern Switzerland
| | - Ursula Wanzenried
- Clinical Pharmacology Laboratory; Institute for Infectious Diseases; University of Bern; Bern Switzerland
| | - Jeannette Schiess
- Clinical Pharmacology Laboratory; Institute for Infectious Diseases; University of Bern; Bern Switzerland
| | - Christian Lanz
- Laboratory of Phytopharmacology, Bioanalytics and Pharmacokinetics; Department of Clinical Research; University of Bern; Bern Switzerland
| | - Wolfgang Thormann
- Clinical Pharmacology Laboratory; Institute for Infectious Diseases; University of Bern; Bern Switzerland
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13
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Joneli J, Wanzenried U, Schiess J, Lanz C, Caslavska J, Thormann W. Determination of carbohydrate-deficient transferrin in human serum by capillary zone electrophoresis: Evaluation of assay performance and quality assurance over a 10-year period in the routine arena. Electrophoresis 2013; 34:1563-71. [DOI: 10.1002/elps.201200653] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 02/21/2013] [Accepted: 03/05/2013] [Indexed: 11/06/2022]
Affiliation(s)
- Jeannine Joneli
- Clinical Pharmacology Laboratory; Institute for Infectious Diseases; University of Bern; Bern; Switzerland
| | - Ursula Wanzenried
- Clinical Pharmacology Laboratory; Institute for Infectious Diseases; University of Bern; Bern; Switzerland
| | - Jeannette Schiess
- Clinical Pharmacology Laboratory; Institute for Infectious Diseases; University of Bern; Bern; Switzerland
| | - Christian Lanz
- Department of Clinical Research; Laboratory of Phytopharmacology; Bioanalytics and Pharmacokinetics; University of Bern; Bern; Switzerland
| | - Jitka Caslavska
- Clinical Pharmacology Laboratory; Institute for Infectious Diseases; University of Bern; Bern; Switzerland
| | - Wolfgang Thormann
- Clinical Pharmacology Laboratory; Institute for Infectious Diseases; University of Bern; Bern; Switzerland
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Kuroda Y, Hamaguchi R, Moriyama K, Tanimoto T, Haginaka J. Improved capillary electrophoresis method for the analysis of carbohydrate-deficient transferrin in human serum, avoiding interference by complement C3. J Pharm Biomed Anal 2013; 76:81-6. [DOI: 10.1016/j.jpba.2012.12.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Revised: 12/08/2012] [Accepted: 12/10/2012] [Indexed: 10/27/2022]
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15
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Mesbah K, Verpillot R, de L'escaille F, Falmagne JB, Taverna M. Contribution of CE to the analysis of protein or peptide biomarkers. Methods Mol Biol 2013; 984:167-190. [PMID: 23386344 DOI: 10.1007/978-1-62703-296-4_13] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Biomarker analysis is pivotal for disease diagnosis and one important class of biomarkers is constituted by proteins and peptides. This review focuses on protein and peptide analyses from biological fluids performed by capillary electrophoresis. The various strategies that have been reported to prevent difficulties due to the handling of real samples are described. Innovative techniques to overcome the complexity of the sample, to prevent the adsorption of the analytes on the inner capillary wall, and to increase the sensibility of the analysis are summarized and illustrated by different applications. To fully illustrate the contribution of CE to the analysis of biomarkers from human sample, two detailed protocols are given: the analysis from CSF of five amyloid peptide, biomarkers of the Alzheimer disease, and the analysis of sialoforms of transferrin from human serum.
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Affiliation(s)
- Kiarach Mesbah
- Laboratory of Proteins and Nanotechnologies in Separation Sciences, Faculté de Pharmacie, University of Paris-Sud, UMR-CNRS 8612, Châtenay-Malabry, France
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16
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Affiliation(s)
- Jitka Caslavska
- Clinical Pharmacology Laboratory; Institute for Infectious Diseases; University of Bern; Bern; Switzerland
| | - Wolfgang Thormann
- Clinical Pharmacology Laboratory; Institute for Infectious Diseases; University of Bern; Bern; Switzerland
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17
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Caslavska J, Joneli J, Wanzenried U, Schiess J, Thormann W. Transferrin immunoextraction for determination of carbohydrate-deficient transferrin in human serum by capillary zone electrophoresis. J Sep Sci 2012; 35:3521-8. [DOI: 10.1002/jssc.201200712] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Revised: 08/21/2012] [Accepted: 08/22/2012] [Indexed: 11/11/2022]
Affiliation(s)
- Jitka Caslavska
- Clinical Pharmacology Laboratory; Institute for Infectious Diseases; University of Bern; Bern Switzerland
| | - Jeannine Joneli
- Clinical Pharmacology Laboratory; Institute for Infectious Diseases; University of Bern; Bern Switzerland
| | - Ursula Wanzenried
- Clinical Pharmacology Laboratory; Institute for Infectious Diseases; University of Bern; Bern Switzerland
| | - Jeannette Schiess
- Clinical Pharmacology Laboratory; Institute for Infectious Diseases; University of Bern; Bern Switzerland
| | - Wolfgang Thormann
- Clinical Pharmacology Laboratory; Institute for Infectious Diseases; University of Bern; Bern Switzerland
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Pascali JP, Bortolotti F, Sorio D, Ivanova M, Palmbach TM, Tagliaro F. Improved capillary electrophoresis determination of carbohydrate-deficient transferrin including on-line immunosubtraction. MEDICINE, SCIENCE, AND THE LAW 2011; 51:26-31. [PMID: 21595418 DOI: 10.1258/msl.2011.010031] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The instrumental analysis of carbohydrate-deficient transferrin (CDT), a recognized marker of chronic alcohol abuse, is most commonly carried out by high-performance liquid chromatography (HPLC) or capillary zone electrophoresis (CZE). Between these two techniques, CZE shows higher efficiency and productivity, but is often reported to be inferior to HPLC in terms of selectivity, because of a less specific ultraviolet detection wavelength than HPLC. On these grounds, the present work was aimed at the development of an improved CZE method for CDT determination, including an on-line immunosubtraction step specifically aimed at enhancing the analytical specificity of CZE determination. The analytical conditions were as follows: uncoated fused silica capillary, 30 microm x 60 cm (L = 50 cm to detector); running buffer, 100 mmol/L borate and 6 mmol/L DAB (1,4-diaminobutane), pH 8.3; voltage, 30 kV; temperature, 25 degrees C; detection, 200 nm. Under the described CZE conditions, a baseline separation between all the CDT related peaks was achieved with good analytical performances in terms of both precision and accuracy. In order to achieve unequivocal recognition of the CDT peaks, an in-capillary immunosubtraction step was included by loading a plug of anti-human transferrin antibody solution after the sample plug. This analytical approach was applied successfully to recognize CDT peaks in the presence of potential interferences.
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Affiliation(s)
- Jennifer P Pascali
- Department of Public Health and Community Medicine, Unit of Forensic Medicine, University of Verona, Verona, Italy
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20
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Alahmad Y, Thuy Tran N, Duboeuf J, Grégoire A, Rancé I, Taverna M. CZE for glycoform profiling and quality assessment of recombinant human interleukin-7. Electrophoresis 2009; 30:2347-54. [DOI: 10.1002/elps.200800789] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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21
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Stutz H. Protein attachment onto silica surfaces - a survey of molecular fundamentals, resulting effects and novel preventive strategies in CE. Electrophoresis 2009; 30:2032-61. [DOI: 10.1002/elps.200900015] [Citation(s) in RCA: 114] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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22
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Lanz C, Falmagne JB, de l’Escaille F, Marti U, Thormann W. Determination of carbohydrate-deficient transferrin in human serum with capillary zone electrophoresis. J Chromatogr A 2008; 1206:33-40. [DOI: 10.1016/j.chroma.2008.05.025] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2008] [Revised: 05/07/2008] [Accepted: 05/09/2008] [Indexed: 01/03/2023]
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23
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Marti U, Joneli J, Caslavska J, Thormann W. Determination of carbohydrate-deficient transferrin in human serum by two capillary zone electrophoresis methods and a direct immunoassay: Comparison of patient data. J Sep Sci 2008; 31:3079-87. [DOI: 10.1002/jssc.200800314] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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24
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Capillary electrophoresis analysis of biofluids with a focus on less commonly analyzed matrices. J Chromatogr B Analyt Technol Biomed Life Sci 2008; 866:154-66. [DOI: 10.1016/j.jchromb.2008.01.058] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2007] [Revised: 01/23/2008] [Accepted: 01/24/2008] [Indexed: 12/19/2022]
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25
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Lucy CA, MacDonald AM, Gulcev MD. Non-covalent capillary coatings for protein separations in capillary electrophoresis. J Chromatogr A 2008; 1184:81-105. [DOI: 10.1016/j.chroma.2007.10.114] [Citation(s) in RCA: 252] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2007] [Revised: 10/25/2007] [Accepted: 10/31/2007] [Indexed: 11/27/2022]
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26
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Schellenberg F, Girre C, Nalpas B, Plat A, Tome A, Pagès JC. Analytical evaluation of a new capillary electrophoresis method for carbohydrate-deficient transferrin measurement. Clin Chim Acta 2007; 382:48-53. [PMID: 17467678 DOI: 10.1016/j.cca.2007.03.020] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2007] [Revised: 03/16/2007] [Accepted: 03/17/2007] [Indexed: 10/23/2022]
Abstract
BACKGROUND Carbohydrate-deficient transferrin (CDT), the sum of a- and disialotransferrin, is considered the most efficient routine biological marker of alcohol abuse. In recent years, methods based on capillary zone electrophoresis (CZE) have been developed using specialized monocapillary systems. These are characterized by a high analytical detection level, counterbalanced by a poor productivity. We evaluated a new CZE method for CDT measurement on the Sebia Capillarys, an eight-capillary system developed for routine serum capillary electrophoresis. METHODS Precision and possible biases due to abnormal (low or high) transferrin levels or lipemic samples were assessed. Exactitude and precision were tested by comparison with a HPLC procedure acknowledged to be the most reliable to date. The validity of the manufacturer's cut-off was checked by measuring CDT in a population comprising abstaining patients, moderate alcohol consumers and alcohol abusers. Lastly, the method was compared to the routine %CDT TIA and N Latex CDT methods. RESULTS The imprecision was 18.5% at the minimum detection level and decreased to 6.1% for high CDT values. No significant shift in the CDT results was observed in relation to abnormally low or high serum transferrin, or in lipemic samples. A high level of concordance was observed with the HPLC method used as reference. The results were strongly correlated with both other routine methods (r>0.90). The diagnostic values were comparable to the literature data, even if differences in the studied populations make difficult a direct comparison of the results. Our data suggested that the cut-off could be raised from 1.3% to 1.4% to reduce the number of false positive values without loss of diagnostic efficiency. CONCLUSIONS This Capillarys method from Sebia showed good precision as compared to those published using other CZE methods. Capillarys method correlated well with HPLC and two routine methods. However, we noticed significant bias at low CDT concentrations. Therefore, with the advantage of high throughput and full automation, these results indicate that the new method is a consistent alternative to the other methods proposed for routine CDT measurement.
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Affiliation(s)
- François Schellenberg
- CHRU de Tours, Pôle de Biologie, Laboratoire de Biochimie, Hôpital Trousseau, France.
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28
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Tagliaro F, Bortolotti F, Pascali JP. Current role of capillary electrophoretic/electrokinetic techniques in forensic toxicology. Anal Bioanal Chem 2007; 388:1359-64. [PMID: 17572886 DOI: 10.1007/s00216-007-1381-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2007] [Revised: 05/21/2007] [Accepted: 05/22/2007] [Indexed: 11/29/2022]
Abstract
The current application of capillary electrophoresis in forensic toxicology has been critically reviewed with special focus on the areas where this technique has shown real advantages over chromatographic methods. For example, capillary electrophoresis has been most successfully applied to the chiral analysis of some drugs of forensic interest, including amphetamines and their congeners. Another typical application field of capillary electrophoresis is represented by protein analysis. Recently, special interest has been paid to carbohydrate deficient transferrin (CDT), the most important biological marker of chronic alcohol abuse. Other specific applications of capillary electrophoresis of potential forensic toxicological concern are also discussed. The review includes 62 references.
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Affiliation(s)
- Franco Tagliaro
- Department of Medicine and Public Health, Section of Forensic Medicine, University of Verona, Policlinico G.B. Rossi, P.le L.A. Scuro, 37134 Verona, Italy.
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29
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Sanz-Nebot V, Balaguer E, Benavente F, Neusüss C, Barbosa J. Characterization of transferrin glycoforms in human serum by CE-UV and CE-ESI-MS. Electrophoresis 2007; 28:1949-57. [PMID: 17523137 DOI: 10.1002/elps.200600648] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Human transferrin (Tf) is a model glycoprotein for congenital disorders of glycosylation (CDG) diagnosis. In the last few years, new CE-UV methods for intact Tf glycoforms analysis have been developed using nonvolatile BGEs and organic modifiers. However, the use of these BGEs does not allow the coupling of these procedures with electrospray MS (ESI-MS). In this study, a new CE-UV separation method of Tf glycoforms is developed, using a double-layer stable coating and a volatile BGE based on ammonium acetate. The separation method is optimized using standard Tf and their potential is demonstrated applying the method to the analysis of sera Tf from healthy individuals and CDG patients. The CE-UV separation method has been coupled to ESI-MS detection. Main parameters such as sheath liquid composition are optimized in order to obtain a good sensitivity. The CE-ESI-MS method has also been used in serum samples obtaining the separation of the different proteins present in serum and partial separation of Tf glycoforms. Different mass spectra and deconvoluted molecular masses were obtained for each sialoform, allowing unequivocal glycoform identification.
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30
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Robb CS. Applications of Physically Adsorbed Polymer Coatings in Capillary Electrophoresis. J LIQ CHROMATOGR R T 2007. [DOI: 10.1080/10826070701191029] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Christina S. Robb
- a Department of Analytical Chemistry , Connecticut Agricultural Experiment Station , New Haven , Connecticut , USA
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31
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Abstract
Bidirectional ITP in fused-silica capillaries double-coated with Polybrene and poly-(vinylsulfonate) is a robust approach for analysis of low-molecular-mass compounds. EOF towards the cathode is strong (mobility >4.0 x 10(-8) m(2)/Vs) within the entire pH range investigated (2.40-8.08), dependent on ionic strength and buffer used and, at constant ionic strength, higher at alkaline pH. Electrokinetic separations and transport in such coated capillaries can be described with a dynamic computer model which permits the combined simulation of electrophoresis and electroosmosis in which the EOF is predicted either with a constant (i.e. pH- and ionic strength-independent) or a pH- and ionic strength-dependent electroosmotic mobility. Detector profiles predicted by computer simulation agree qualitatively well with bidirectional isotachopherograms that are monitored with a setup comprising two axial contactless conductivity detectors and a UV absorbance detector. The varying EOF predicted with a pH- and ionic strength-dependent electroosmotic mobility can be regarded as being realistic.
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Affiliation(s)
- Jitka Caslavska
- Department of Clinical Pharmacology, University of Bern, Bern, Switzerland
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32
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Joneli J, Lanz C, Thormann W. Capillary zone electrophoresis determination of carbohydrate-deficient transferrin using the new CEofix reagents under high-resolution conditions. J Chromatogr A 2006; 1130:272-80. [PMID: 16777120 DOI: 10.1016/j.chroma.2006.05.035] [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] [Received: 02/16/2006] [Revised: 04/27/2006] [Accepted: 05/15/2006] [Indexed: 11/18/2022]
Abstract
Capillary zone electrophoresis (CZE) with a dynamic double coating based on the new CEofix reagents is shown to provide high-resolution separations of serum transferrin (Tf) isoforms, a prerequisite for the monitoring of unusual and complex Tf patterns, including those seen with genetic variants and disorders of glycosylation. A 50 microm I.D. fused-silica capillary of 60 cm total length, an applied voltage of 20 kV and a capillary temperature of 30 degrees C results in 15 min CZE runs of high assay precision and thus provides a robust approach for the determination of carbohydrate-deficient transferrin (CDT, sum of asialo-Tf and disialo-Tf in relation to total Tf) in human serum. Except for selected samples of patients with severe liver diseases and sera with high levels of paraproteins, interference-free Tf patterns are detected. Compared with the use of the previous CEofix reagents for CDT under the same instrumental conditions, the resolution between disialo-Tf and trisialo-Tf is significantly higher (1.7 versus 1.4). The CDT levels of reference and patient sera are comparable, suggesting that the new assay can be applied for screening and confirmation analyses. The high-resolution CZE assay represents an attractive alternative to HPLC and can be regarded as a candidate of a reference method for CDT.
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Affiliation(s)
- Jeannine Joneli
- Department of Clinical Pharmacology, University of Bern, Murtenstrasse 35, CH-3010 Bern, Switzerland
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33
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Jabeen R, Payne D, Wiktorowicz J, Mohammad A, Petersen J. Capillary electrophoresis and the clinical laboratory. Electrophoresis 2006; 27:2413-38. [PMID: 16718719 DOI: 10.1002/elps.200500948] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Over the past 15 years, CE as an analytical tool has shown great promise in replacing many conventional clinical laboratory methods, such as electrophoresis and HPLC. CE's appeal was that it was fast, used very small amounts of sample and reagents, was extremely versatile, and was able to separate large and small analytes, whether neutral or charged. Because of this versatility, numerous methods have been developed for analytes that are of clinical interest. Other than molecular diagnostic and forensic laboratories CE has not been able to make a major impact in the United States. In contrast, in Europe and Japan an increasing number of clinical laboratories are using CE. Now that automated multicapillary instruments are commercially available along with cost-effective test kits, CE may yet be accepted as an instrument that will be routinely used in the clinical laboratories. This review will focus on areas where CE has the potential to have the greatest impact on the clinical laboratory. These include analyses of proteins found in serum and urine, hemoglobin (A1c and variants), carbohydrate-deficient transferrin, forensic and therapeutic drug screening, and molecular diagnostics.
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Affiliation(s)
- Rukhsana Jabeen
- University of Texas Medical Branch--Pathology, Galveston, TX 77555-0551, USA
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34
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Bortolotti F, De Paoli G, Tagliaro F. Carbohydrate-deficient transferrin (CDT) as a marker of alcohol abuse: a critical review of the literature 2001-2005. J Chromatogr B Analyt Technol Biomed Life Sci 2006; 841:96-109. [PMID: 16725384 DOI: 10.1016/j.jchromb.2006.05.005] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2006] [Revised: 05/03/2006] [Accepted: 05/04/2006] [Indexed: 01/21/2023]
Abstract
The diagnosis of alcohol abuse based on objective data is a necessary requirement in both clinical and forensic environments. Among the different biomarkers of chronic alcohol abuse, carbohydrate-deficient transferrin (CDT) is world wide recognized as the most reliable indicator. However, several problems about the real meaning of CDT and the reliability of its use for the diagnosis of alcohol abuses are still open, as reported by numerous research articles and reviews. The present article presents a critical review of the literature on CDT appeared in the period from 2001 to 2005 (included). The article is organized in the following sections: (1) introduction, (2) definition and structure of human serum CDT, (3) pathomechanisms of the ethanol-induced CDT increase, (4) preanalysis, (5) analysis, (6) data interpretation, (7) review papers, (8) conclusions. As many as 127 papers appeared in the international literature and retrieved by the search engines PubMed and Scopus are quoted.
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Affiliation(s)
- Federica Bortolotti
- University of Verona, Department Medicine/Public Health, Chair of Forensic Medicine, Policlinico G.B. Rossi, I-37134 Verona, Italy
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35
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Souverain S, Geiser L, Rudaz S, Veuthey JL. Strategies for rapid chiral analysis by capillary electrophoresis. J Pharm Biomed Anal 2006; 40:235-41. [PMID: 16153797 DOI: 10.1016/j.jpba.2005.07.023] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2005] [Revised: 06/30/2005] [Accepted: 07/06/2005] [Indexed: 11/29/2022]
Abstract
The aim of this study was to investigate four strategies to decrease chiral CE analysis time: (1) short-end injection technique, (2) high electric field through a capillary length reduction, (3) external pressure application and (4) capillary dynamically coated to generate an important electroosmotic flow. These approaches were applied for a simultaneous enantiomeric separation of amphetamine and four related compounds using a neutral derivatised cyclodextrin (hydroxypropyl-beta-cyclodextrin) as chiral selector. Analysis time and CE performances, in terms of peak efficiency and resolution, were examined. Among the investigated strategies, the dynamic coating procedure appeared to be the most suitable approach to decrease analysis time (inferior to 7 min) and improve sensitivity. Furthermore, it exhibited very good migration time repeatability (0.1%). This benefit is of utmost interest in chiral analysis for an unambiguous peak identification, especially for a complex mixture such as reported in this study.
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Affiliation(s)
- Sandrine Souverain
- Laboratory of Pharmaceutical Analytical Chemistry, School of Pharmaceutical Sciences, University of Geneva, Bd d'Yvoy 20, 1211 Geneva 4, Switzerland
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36
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Tagliaro F, Bortolotti F. Recent advances in the applications of CE to forensic sciences (2001–2004). Electrophoresis 2006; 27:231-43. [PMID: 16421953 DOI: 10.1002/elps.200500697] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The present article reviews the applications of CE in forensic science covering the period from 2001 until the first part of 2005. The overview includes the most relevant examples of analytical applications of capillary electrophoretic and electrokinetic techniques in the following fields: (i) Forensic drugs and poisons, (ii) explosive analysis and gunshot residues, (iii) small ions of forensic interest, (iv) forensic DNA and RNA analysis, (v) proteins of forensic interest, and (vi) ink analysis.
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Affiliation(s)
- Franco Tagliaro
- Department of Public Medicine and Health, Section of Forensic Medicine, University of Verona, Verona, Italy.
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37
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Bortolotti F, De Paoli G, Pascali JP, Trevisan MT, Floreani M, Tagliaro F. Analysis of Carbohydrate-Deficient Transferrin: Comparative Evaluation of Turbidimetric Immunoassay, Capillary Zone Electrophoresis, and HPLC. Clin Chem 2005; 51:2368-71. [PMID: 16306099 DOI: 10.1373/clinchem.2005.051805] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Federica Bortolotti
- Department of Medicine and Public Health, Unit of Forensic Medicine, University of Verona, University Hospital (Policlinico), Italy
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38
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Arizaga Rodríguez S, Blanco González E, Alvarez Llamas G, Montes-Bayón M, Sanz-Medel A. Detection of transferrin isoforms in human serum: comparison of UV and ICP–MS detection after CZE and HPLC separations. Anal Bioanal Chem 2005; 383:390-7. [PMID: 16041604 DOI: 10.1007/s00216-005-3217-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2005] [Revised: 02/28/2005] [Accepted: 03/18/2005] [Indexed: 10/25/2022]
Abstract
Two methods for separation of transferrin (Tf) sialoforms, capillary electrophoresis (CE) and high performance liquid chromatography (HPLC) with conventional UV absorbance detection, have been investigated and compared. First, conditions affecting the separation of the Tf isoforms by capillary zone electrophoresis and HPLC were carefully optimized. The use of 15 mmol L(-1) borate buffer (pH 8.4) containing 3 mmol L(-1) diaminobutane (DAB) as additive enabled good separation of the Tf isoforms by CE (75 cm x 50 microm i.d. fused silica capillary) at 25 kV. In HPLC, a gradient of ammonium acetate (from 0 to 250 mmol L(-1) in 45 min) buffered at pH 6 (Tris-HCl) proved suitable for separation of Tf isoforms on a Mono-Q HR 5/5 anion-exchange column. On-line specific detection of the iron associated with the different Tf isoforms, after Fe saturation, by inductively coupled plasma mass spectrometry (ICP-MS) was studied in detail to compare its analytical performance with UV detection. For both CE and HPLC an octapole reaction system (ORS) ICP-MS instrument was used to minimize polyatomic interferences on the (56)Fe major isotope. Limits of detection of the different isoforms were in the range of 0.02-0.04 micromol L(-1) Tf for HPLC-ICP (ORS)-MS. This hybrid technique proved more selective and reliable detection of transferrin isoforms with 2, 3, 4, 5, and 6 sialic acid residues (S(2), S(3), S(4), S(5), and S(6)) in real serum samples. Interesting results from iron speciation of Tf in serum from healthy individuals and from pregnant women are given.
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Affiliation(s)
- Sandra Arizaga Rodríguez
- Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, C/Julián Clavería 8, 33006 Oviedo, Spain
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39
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Piagnerelli M, Boudjeltia KZ, Nuyens V, De Backer D, Su F, Wang Z, Vincent JL, Vanhaeverbeek M. RAPID ALTERATIONS IN TRANSFERRIN SIALYLATION DURING SEPSIS. Shock 2005; 24:48-52. [PMID: 15988320 DOI: 10.1097/01.shk.0000168524.20588.67] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The inflammatory process is associated with alterations in iron metabolism. Transferrin, an acute-phase N-glycosylated glycoprotein, plays an important role in iron transport. Human serum transferrin contains two biantennary glycans, each consisting of 0 to 4 molecules of sialic acid (SA); its SA content is heterogeneous with high concentration of tetrasialotransferrin (4SA) and low amounts of disialo-, trisialo-, penta-, and hexasialotransferrin. The hepatic uptake of iron is greater for desialylated transferrin isoforms (disialotransferrin) than for the other forms. We hypothesized that serum levels of carbohydrate-deficient transferrin (CDT, disialotransferrin) may increase rapidly in septic patients. Blood samples were obtained from critically ill patients with (n = 15) and without (n = 14) documented sepsis and compared with healthy volunteers. The different forms of transferrin were studied by capillary zone electrophoresis; SA concentrations were measured by enzymatic colorimetric assay. There was a significant increase in the proportion of CDT in septic compared with nonseptic patients and volunteers (18.3% [1.3-30.5] vs. 0.7% [0.5-0.9]; P < 0.01 and 0.9% [0.5-1.1]; P < 0.05). Conversely, tri- and tetrasialotransferrin levels were lower in septic patients. Total and free SA concentrations were significantly higher in septic patients than in healthy volunteers. In a sheep model of septic shock secondary to peritonitis, serum free SA was already increased after 15 h. Sepsis is associated with decreased SA content on circulating transferrin and with an increase in blood free SA concentrations. In view of these rapid modifications and the long half-life of transferrin, the most likely explanation is degradation of transferrin by neuraminidase. Further studies including measurement of blood neuraminidase concentration and activity are needed to understand the process and exact role of SA decrease in septic patients.
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Affiliation(s)
- Michael Piagnerelli
- Department of Intensive Care, Erasme Hospital, Free University of Brussels, Brussels, Belgium
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40
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Chang WWP, Hobson C, Bomberger DC, Schneider LV. Rapid separation of protein isoforms by capillary zone electrophoresis with new dynamic coatings. Electrophoresis 2005; 26:2179-86. [PMID: 15861468 DOI: 10.1002/elps.200410283] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Many cellular functions are regulated through protein isoforms. Changes in the expression level or regulatory dysfunctions of isoforms often lead to developmental or pathological disorders. Isoforms are traditionally analyzed using techniques such as gel- or capillary-based isoelectric focusing. However, with proper electro-osmotic flow (EOF) control, isoforms with small pI differences can also be analyzed using capillary zone electrophoresis (CZE). Here we demonstrate the ability to quickly resolve isoforms of three model proteins (bovine serum albumin, transferrin, alpha1-antitrypsin) in capillaries coated with novel dynamic coatings. The coatings allow reproducible EOF modulation in the cathodal direction to a level of 10(-9) m2V(-1)s(-1). They also appear to inhibit protein adsorption to the capillary wall, making the isoform separations highly reproducible both in peak areas and apparent mobility. Isoforms of transferrin and alpha1-antitrypsin have been implicated in several human diseases. By coupling the CZE isoform separation with standard affinity capture assays, it may be possible to develop a cost-effective analytical platform for clinical diagnostics.
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41
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Golka K, Wiese A. Carbohydrate-deficient transferrin (CDT)--a biomarker for long-term alcohol consumption. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART B, CRITICAL REVIEWS 2004; 7:319-337. [PMID: 15205047 DOI: 10.1080/10937400490432400] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Carbohydrate-deficient transferrin (CDT) is a biomarker for chronic alcohol intake of more than 60 g ethanol/d. It has been reported to be superior to conventional markers like gamma-glutamyltransferase (GGT) and mean corpuscular volume MCV). This review covers theoretical and analytical aspects, with data from controlled drinking experiments and from different population subgroups such as subjects with different liver diseases or different drinking patterns. CDT determinations are particularly indicated in (1) cases of chronic alcohol consumption and relapses after withdrawal, (2) license reapplication after driving under alcohol influence, (3) differentiating patients with enzyme-inducing medication from those with alcohol abuse, 4) congenital disorders of glycosylation such as carbohydrate-deficient glycoprotein syndrome Ia (CDGS Ia), and (5) patients treated for galactosemia. The main advantage of CDT is its high specificity, as evidenced in combination with increased alcohol consumption. CDT values are not markedly influenced by medication except in immunosuppressed patients, who may show low CDT values. In general, CDT values appear less elevated after alcohol intake in women. The main disadvantage is the relatively low sensitivity. Hence, this parameter is not suitable for screening for subjects with alcohol abuse in the general population. As CDT, GGT, and MCV are connected with chronic alcohol consumption by different pathophysiological mechanisms, a combination of these parameters will further improve the diagnostic value.
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Affiliation(s)
- Klaus Golka
- Institute for Occupational Physiology at the University of Dortmund, Dortmund, Germany.
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42
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Carchon HA, Chevigné R, Falmagne JB, Jaeken J. Diagnosis of Congenital Disorders of Glycosylation by Capillary Zone Electrophoresis of Serum Transferrin. Clin Chem 2004; 50:101-11. [PMID: 14633925 DOI: 10.1373/clinchem.2003.021568] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Abstract
Background: Congenital disorders of glycosylation (CDG) are usually diagnosed by isoelectric focusing (IEF) of serum transferrin (Tf). The aim of this study was to evaluate capillary zone electrophoresis (CZE) as a diagnostic alternative to IEF.
Methods: We performed 792 CZE analyses of Tf, using the CEofixTM-CDT (carbohydrate-deficient transferrin) assay. Peak identification was based on relative migration times (RMTs) to reduce migration variability.
Results: Tf profiles comprised three main groups (A–C). Groups A and B were characterized by one or two dominant tetrasialo-Tf peaks, whereas group C showed a widely variable Tf isoform composition. Group A was composed of four subgroups: a major group with a typical Tf profile (considered as reference group), two minor groups with decreased or moderately increased trisialo-Tf isoform, and a group showing the presence of unknown compounds with RMTs similar to mono- and disialo-Tf. However, these compounds were absent on IEF. Group C contained all profiles from patients with confirmed as well as putative CDG. From the reference group, 99% confidence intervals were calculated for the RMTs of the Tf isoforms, and percentiles representing the Tf isoform distributions were defined.
Conclusions: All patients with abnormal IEF results and confirmed CDG were identified by CZE; thus, this method can be used as a diagnostic alternative to IEF in a manner suitable for automation. Because whole serum is analyzed, it should be kept in mind that CZE profiles can show substances other than Tf.
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Affiliation(s)
- Hubert A Carchon
- Department of Pediatrics, Center for Metabolic Disease, Katholieke Universiteit Leuven, B-3000 Leuven, Belgium.
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43
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Abstract
Abstract
Background: There is need for a reference method for transferrin glycoforms in serum to which routine immunologic methods for the alcohol marker carbohydrate-deficient transferrin (CDT) can be traceable. We describe an improved HPLC method for transferrin glycoforms.
Methods: Transferrin was iron-saturated by mixing the serum with ferric nitrilotriacetic acid, and lipoproteins were precipitated with dextran sulfate and calcium chloride. Separation of glycoforms was performed on a SOURCE 15Q anion-exchange column using salt gradient elution. Quantification relied on selective absorbance of the iron–transferrin complex at 470 nm. The relative amount of each glycoform was calculated as a percentage of the area under the curve, using baseline integration.
Results: The HPLC system provided reproducible separation and quantification of the asialo-, monosialo-, disialo-, trisialo-, tetrasialo-, pentasialo-, and hexasialotransferrin glycoforms. Most importantly, disialo- and trisialotransferrin were almost baseline separated. The intra- and interassay CV for disialotransferrin were <5%. Serum and the pretreated samples were stable for at least 2 days at 22 or 4 °C. Sera from 132 healthy controls contained [mean (SD)] 1.16 (0.25)% disialotransferrin, 4.77 (1.36)% trisialotransferrin, 80.18 (2.01)% tetrasialotransferrin, and 13.88 (1.69)% pentasialo- + hexasialotransferrin. In some cases of a high (>6%) trisialotransferrin, monosialotransferrin was detected at <0.25%. Asialotransferrin was not detected in control sera, but was detected in 57% of chronic heavy drinkers and in 62% of sera with ≥2% disialotransferrin.
Conclusions: The HPLC method fulfills the requirements of a preliminary reference method for CDT and should work for any combination of serum transferrin glycoforms. This method could also be useful for confirming positive CDT results by immunoassays in medico-legal cases.
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Affiliation(s)
- Anders Helander
- Department of Clinical Neuroscience, Karolinska Institutet and Hospital, SE-171 76 Stockholm, Sweden.
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44
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Ramdani B, Nuyens V, Codden T, Perpete G, Colicis J, Lenaerts A, Henry JP, Legros FJ. Analyte Comigrating with Trisialotransferrin during Capillary Zone Electrophoresis of Sera from Patients with Cancer. Clin Chem 2003; 49:1854-64. [PMID: 14578317 DOI: 10.1373/clinchem.2003.019240] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
AbstractBackground: Serum concentrations of monoglycosylated isoforms of transferrin are increased by chronic ethanol intake. We investigated transferrin glycosylation in patients with cancer, in which aberrant glycosylation is also induced.Methods: We used a P/ACE 5000 series capillary zone electrophoresis (CZE) apparatus and a CZE carbohydrate-deficient transferrin reagent set to study 200 cancer patients who consumed alcohol moderately and 33 who were alcohol abusers; we then compared these patients with 56 healthy teetotalers, 89 moderate, and 112 excessive alcohol drinkers without known malignancies. Transferrin isoforms were identified by immunosubtraction with anti-human transferrin polyclonal antibody.Results: Seven peaks, P0–P6, were visualized and completely or partly immunosubtracted when CZE separation was performed at pH 8.5. P0 was present in 95% of alcohol abusers with or without cancer. P3 was significantly higher in cancer patients and was only partly immunosubtracted as trisialotransferrin in all groups. The comigrating analyte was not altered by papain, precipitation by ethanol, or extraction by organic solvents, but was sensitive to acid hydrolysis, suggesting a polysaccharide structure. When isolated at pH 8.25, this analyte was higher in cancer patients. ROC curve analysis identified localized malignant neoplasia at P3 values above 5.8% of total transferrin (sensitivity, 0.78; specificity, 0.87), regardless of alcohol consumption. Disseminated cancers were better differentiated above 8% (sensitivity, 0.94; specificity, 0.96).Conclusions: Malignant neoplasia, unlike excessive ethanol intake, did not alter the addition of two N-glycans to transferrin. A peak comigrating with trisialotransferrin had characteristics of a polysaccharide in all adults and was increased in sera of patients with cancer.
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Affiliation(s)
- Brahim Ramdani
- University Department of Gastroenterology, Centre Hospitalier Universitaire de Charleroi, 92, Boulevard Janson, 6000 Charleroi, Belgium
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Lanz C, Marti U, Thormann W. Capillary zone electrophoresis with a dynamic double coating for analysis of carbohydrate-deficient transferrin in human serum. J Chromatogr A 2003; 1013:131-47. [PMID: 14604115 DOI: 10.1016/s0021-9673(03)00566-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Capillary zone electrophoresis (CZE) with a dynamic double coating permits the simultaneous, individual, quantitative determination of transferrin (Tf) isoforms in human serum and thus carbohydrate-deficient transferrin (CDT), the most specific marker available today for the detection of chronic, excessive alcohol intake. CZE of serum Tf was carefully evaluated using the P/ACE MDQ with fused-silica capillaries of 50 microm I.D. and 60.2 cm total length, the CEofix CDT kit and the instrumental conditions recommended by the kit manufacturer. The precision performance assessed over a 20-day period according to the internationally accepted NCCLS EP5-A guidelines revealed the CZE assay as being highly reproducible with within-run and total precision being dependent on the Tf isoform level and RSD values ranging between 2.2 and 17.6%. Inter-day RSD values for asialo-Tf were noted to be between 9.8 and 11.5% and for disialo-Tf between 3.8 and 8.6%, whereas those for CDT levels of 0.87 and 4.31% of total Tf were determined to be 8.6 and 3.4%, respectively. The RSD values for trisialo-Tf, tetrasialo-Tf, pentasialo-Tf and hexasialo-Tf were found to be between 0.4 and 4.1%. Tf patterns are recognized and identified via detection times of Tf isoforms (intra-day and inter-day RSD values < 1.0% and < 1.7%, respectively), immunosubtraction of Tf and enzymatic sequential cleavage of sialic acid residues. Furthermore, heterozygous Tf BC and Tf CD variants are assigned via spiking with a known mixture of Tf isoforms (e.g. the serum of a healthy Tf C homozygote). Among the non-Tf peaks monitored, the CRP peak detected shortly before disialo-Tf was identified by immunosubtraction and peak magnitudes were found to correlate well with immunochemically determined CRP serum levels. The CZE assay with dynamic double coating could thereby be shown to be sensitive enough to determine elevated CRP levels in human serum. Furthermore, unusual peaks in the gamma-region were identified by customary serum protein CZE, immunosubtraction CZE and immunofixation.
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Affiliation(s)
- Christian Lanz
- Department of Clinical Pharmacology, University of Berne, Murtenstrasse 35, CH-3010 Berne, Switzerland
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