Academic literature on the topic 'Electrophoresi'

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Journal articles on the topic "Electrophoresi"

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Surh, Linda C., Gary G. Shutler, and Robert G. Korneluk. "Simple, Rapid Detection of PCR Heteroduplexes in DNA Mutations and Polymorphisms." Clinical Chemistry 37, no. 12 (December 1, 1991): 2142. http://dx.doi.org/10.1093/clinchem/37.12.2142.

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Abstract Detection of nucleotide differences is fundamental among diverse procedures used to study DNA mutations and polymorphisms, whether for basic molecular research or for diagnosis of genetic disorders. Rapid and efficient analysis without radioactive, chemical, or enzymatic modification is currently possible when polymerase chain reaction (PCR) products are electrophoresed on small polyacrylamide gels (5.0 cm × 4.3 cm × 0.45 mm) and stained with silver. The PhastSystemmTM (Pharmacia LKB Biotechnology, Uppsala, Sweden) was initially developed for protein electrophoresis/isoelectric focusing (1) and involves horizontal electrophoresis with an automated staining unit. We have adapted this system to heteroduplex formation of nucleic acids to detect the most frequent mutation in cystic fibrosis (CF), designated ΔF508 (2). This system offers the advantages and uniformity of semi-automated polyacrylamide electrophoresis in a DNA clinical laboratory and the convenience of precast polyacrylamide gels, rapid electrophoretic times (<30 min), and an automated developing chamber where picogram quantities of DNA can be reproducibly silver-stained. Because pre-packaged agarose buffer strips are used, one need not prepare buffer solutions.
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Manoussopoulos, I. N., E. Maiss, and M. Tsagris. "Native electrophoresis and Western blot analysis (NEWeB): a method for characterization of different forms of potyvirus particles and similar nucleoprotein complexes in extracts of infected plant tissues." Journal of General Virology 81, no. 9 (September 1, 2000): 2295–98. http://dx.doi.org/10.1099/0022-1317-81-9-2295.

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A combination of native electrophoresis and immunodetection (Western blot) was used for the characterization of nucleoprotein particles of the potyvirus Plum pox virus (PPV). Virus particles were electrophoresed directly from plant extracts in agarose or mixed acrylamide–agarose gels under native conditions, blotted on nitrocellulose membranes, and characterized with the aid of a coat protein-specific antibody. Using this combined methodology, called NEWeB (native electrophoresis and Western blotting), we could show that a population of particles that differ in their electrophoretic mobility can be detected in extracts of Nicotiana benthamiana, that two different strains of PPV can be distinguished in double infections of the same plant and that virus particles from leaves contain detectable levels of helper component proteinase molecules. The potential of the NEWeB method for the study of structure and function of virus particles and similar nucleoprotein complexes in single and mixed infections is discussed.
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DelGaudio, John M., William R. Carroll, James J. Sciote, and Ramon M. Esclamado. "Atypical Myosin Heavy Chain in Rat Laryngeal Muscle." Annals of Otology, Rhinology & Laryngology 104, no. 3 (March 1995): 237–45. http://dx.doi.org/10.1177/000348949510400310.

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The myosin content of rat posterior cricoarytenoid and thyroarytenoid muscles was described by means of histochemical, immunohistochemical, and electrophoretic techniques. Laryngeal muscles were dissected and frozen, together with other muscles (extraocular, diaphragm, extensor digitorum longus, and soleus) for comparative purposes, then sectioned serially and stained: 1) histochemically for myofibrillar adenosine triphosphatase reactivity and 2) immunohistochemically for myosin heavy chain (MHC) content with six different antibodies. Other portions of the muscle samples were electrophoresed by a glycerol sodium dodecyl sulfatepolyacrylamide gel electrophoresis technique that separates the MHC protein into its specific isoforms. In electrophoretic comparison it limb muscles, the laryngeal muscles contained an additional MHC band we designated as type IIL (type II laryngeal) MHC. On histochemical and immunohistochemical staining, no fibers from the thyroarytenoid muscle and few fibers from the posterior cricoarytenoid muscle could be classified according to the standard fiber type categories established for limb muscles (types I, IIA, IIB, and IIX). These laryngeal muscle fibers appear to represent an atypical fiber type.
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Esser, K. A., M. O. Boluyt, and T. P. White. "Separation of cardiac myosin heavy chains by gradient SDS-PAGE." American Journal of Physiology-Heart and Circulatory Physiology 255, no. 3 (September 1, 1988): H659—H663. http://dx.doi.org/10.1152/ajpheart.1988.255.3.h659.

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Separation of alpha- and beta-myosin heavy chains (MHCs) in cardiac ventricles of rats by gradient sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was accomplished and compared with the separation of myosin isozymes obtained with pyrophosphate gels. Whole muscle homogenates were electrophoresed on a 4–9% linear gradient SDS polyacrylamide gel for 3–4 h. MHC bands were identified by the migration distance relative to a MHC standard and immunoblot results with a monoclonal antibody to MHC. The MHC bands were further identified as alpha and beta based on the electrophoretic mobility of ventricular homogenates from hypothyroid and hyperthyroid rats and ventricular and slow soleus skeletal muscle homogenates from control rats. The beta-MHC migrated faster than alpha-MHC, and laser densitometry revealed separate peaks when both MHCs were present. With homogenates containing MHC ranging from 0 to 100% alpha, the separation of MHCs with gradient SDS-PAGE correlated highly (r = 0.97) with separation of myosin isozymes by pyrophosphate gel electrophoresis. The SDS-PAGE technique reported herein is a quick, valid, and direct method for the identification and quantification of ventricular MHCs.
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Koel, M., and M. Vaher. "Electrophoretic mobilities in nonaqueos capillary electrophoresis." Proceedings of the Estonian Academy of Sciences. Chemistry 53, no. 1 (2004): 36. http://dx.doi.org/10.3176/chem.2004.1.04.

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Sontag, Tuula, and Hannu Salovaara. "PAG electrophoregrams of wheat cultivars grown in Finland." Agricultural and Food Science 57, no. 4 (December 1, 1985): 271–77. http://dx.doi.org/10.23986/afsci.72203.

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The polyacrylamide gel electrophoretic (PAGE) patterns of gliadins of 9 spring wheat cultivars (Apu, Drabant, Taava, Tapio, Ulla, Kadett, Luja, Ruso and Tähti) and of 5 winter wheat cultivars (Aura, Ilves, Linna, Nisu and Vakka) were determined. Most of the samples studied had specific gliadin PAGE patterns, indicating that electrophoregrams obtained with the procedure employed here can be used for identifying wheat cultivars grown in Finland. Only two cultivars, Taava and Ruso, which are close relatives, possessed similar PAGE patterns. The procedure uses a commercial vertical electrophoresis apparatus and thin gels. Up to 28 samples could be electrophoresed in three hours and analyzed after staining. The procedure can be applied in the identification of wheat cultivars currently grown in Finland.
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Zarubina, Anastasiya O., and Margarita Sergeevna Chernov'yants. "Aqueous and non-aqueous electrophoresis and micellar electrokinetic capillary chromatography of a mixture of quinoline-2-thione and 8-mercaptoquinoline hydrochloride." Analytical Methods 10, no. 12 (2018): 1399–404. http://dx.doi.org/10.1039/c7ay02875j.

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In this paper three variants of the electrophoretic method for the determination of thioamides, quinoline derivatives are given: aqueous capillary electrophoresis, micellar electrokinetic capillary chromatography and non-aqueous electrophoresis.
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Barbosa, J., D. Barrón, and E. Jiménez-Lozano. "Electrophoretic behaviour of quinolones in capillary electrophoresis." Journal of Chromatography A 839, no. 1-2 (April 1999): 183–92. http://dx.doi.org/10.1016/s0021-9673(99)00093-x.

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Sanz-Nebot, V., F. Benavente, I. Toro, and J. Barbosa. "Electrophoretic behavior of peptides in capillary electrophoresis." Journal of Chromatography A 921, no. 1 (June 2001): 69–79. http://dx.doi.org/10.1016/s0021-9673(01)00730-0.

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Sajjadi, Sayyed Hashem, Hossein Ahmadzadeh, and Elaheh K. Goharshadi. "Enhanced electrophoretic separation of proteins by tethered SiO2 nanoparticles in an SDS-polyacrylamide gel network." Analyst 145, no. 2 (2020): 415–23. http://dx.doi.org/10.1039/c9an01759c.

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Tethered nanoparticles (NPs) are able to improve the separation efficiency of proteins in SDS-polyacrylamide gel electrophoresis (SDS-PAGE) due to their capability of enhancing heat dissipation during electrophoresis and restriction of electrophoretic movement of NPs.
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Dissertations / Theses on the topic "Electrophoresi"

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Fu, Shilin. "Prediction of electrophoretic mobilities in capillary zone electrophoresis." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ31347.pdf.

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FINETTI, CHIARA. "NOVEL FUNCTIONAL HYDROPHILIC POLYMERS AND HYDROGELS FOR MICROANALYTICAL SYSTEMS." Doctoral thesis, Università degli Studi di Milano, 2017. http://hdl.handle.net/2434/473212.

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This thesis focuses on the use of hydrophilic polymers for bioanalytical applications, including several microanalytical techniques encompassing nanotechnology, microarray technology and DNA gel electrophoresis. The dissertation is divided in two parts, which share the employment of dimethylacrylamide-based copolymers, developed at the laboratory of Analytical Microsystems of the Institute of Chemistry for Molecular Recognition (National Research Council of Italy) where the thesis has been carried out. PART A introduces a novel approach for surface modification of quantum dots and gold nanoparticles, based on physi-/chemisorption of two different functional dimethylacrylamide copolymers. Beside developing innovative functionalization strategies, the goal is to demonstrate the application of coated nanoparticles in highly sensitive immunoassays based on microarray technology. PART B of the dissertation presents the results of an activity, conducted in collaboration with the company Agilent Technology (UK), aimed at developing an innovative gel sieving matrix for high performance DNA electrophoresis. We introduce a new hydrogel obtained by cross-linking an alkyne modified polymer with an azide one, exploiting a copper catalysed click chemistry reaction. The alkyne functionalized polymer is based on poly(dimethilacrylamide) and it was obtained by a post-polymerization modification approach from the parent copolymer poly(DMA-NAS-MAPS), extensively used in the first part of this dissertation. The azide polymer is a polyethylenglycol terminated with azide groups at both ends, and is commercially available. A considerable part of this work is devoted to the optimization of the characteristics of the new hydrogel, in particular to the extension of its shelf-life, an important parameter in view of its industrial application.
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OTTONE, TIZIANA. "La mutazione di tipo A della nucleofosmina nella diagnosi e nel follow-up della leucemia mieloide acuta." Doctoral thesis, Università degli Studi di Roma "Tor Vergata", 2009. http://hdl.handle.net/2108/1135.

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Acute myeloid leukaemias (AML), which account for about 80% of the acute leukaemias in adult, represent a phenotypically and genetically heterogeneous group of clonal haematopoietic diseases in which, failure to differentiate and over proliferation in the stem cell/progenitor compartment, result in accumulation of non-functional myeloblasts. Nucleophosmin-1 (NPM1) mutations is the most frequent gene alteration in AML (30%), and are particularly frequent in AML with normal karyotype (AML-NK) (60%). These alterations have been shown to carry prognostic significance because they seem to identify patients with better response to chemotherapy. As a consequence, the analysis of NPM1 mutational status is now recommended for inclusion in the genetic routine characterization of AML (Gorello P. et al., Leukemia 2006; Ammatuna E. et al., Clin Chem 2005; Nelida I.N. et al., Leukemia 2005; Scholl S. et al., Leuk Res 2007; Lin LI et al., Leukemia 2006). Finally, given their high prevalence and stability over the course of the disease, NPM1 mutations may serve as an ideal target for minimal residual disease (MRD) assessment, particularly for patients with AML-NK (Gorello P. et al., Leukemia 2006). In early 2005, Falini et al. (Falini B. et al., New Engl J Med 2005) reported that NPM1 gene mutations, mainly consisting of small nucleotide insertion/deletions, occur frequently in AML and are strongly associated with NK. Over 40 different types of mutations in the NPM1 (NPM1m) locus have been described so far, which result in the formation of different mutant proteins. This alterations consist of the insertion/deletion of short nucleotide stretches (4 or 10 bps) after nucleotide position 956 in NPM1 exon 12 that lead to an ORF shift resulting in different protein variants containig novel C-terminus portions. The most common NPM1 mutation is the type A (NPM1 mut-A), accounting for 75% - 85% of cases, and consist of duplication of a TCTG tetranucleotide at position 956 to 959 of the reference sequence (GenBank accession number NM_002520). Available methods to detect nucleophosmin mutations are costly, require sophisticated equipment, and are often less sensitive. The aim of this work was to develop two assays that enable rapid and sensitive detection of NPM1 mut-A (Ottone T. et al., Genes Chromosomes Cancer 2009): a fragment analysis method and an RT-ASO-PCR (Reverse Trascriptase Allele Specific Oligonucleotide Polymerase Chain Reaction) method. Furthermore a semi-nested ASO-PCR method was also designed in order to increase the sensitivity of our assay for the monitoring of MRD. After informed consent, bone marrow and peripheral blood cells were collected at presentation from 107 patients with AML diagnosed at the Institute of Hematology, Department of Biopathology of the University Tor Vergata of Rome. For each patient reverse trascribed cDNA was divided into three aliquotes used for capillary elettrophoresis, sequencing and ASO-PCR. Semi-nested ASO-PCR experiments were carried out using RT-ASO-PCR products. For capillary electrophoresis fluorescent labeled PCR products were used to screen for the presence of NPM1 mutations using the CEQTM 8000 Genetic Analysis Sistem (Beckman Coulter) instrument. Electroferogram showed 348 bp and 352 bp fragment size, corresponding to NPM1wt and NPM1m, respectively. OCI-Aml3 cell line was used as a positive control. The sensitivity of method was tested using the following serial dilutions of the mutated with wild type allele: 0.01, 0.10, 0.25, 0.50, 0.75, 1.00 (mut/wt). To confirm fragment analysis results, 17 NPM1m and 10 NPM1wt samples were sequenced: cDNA were amplified and the products, after purification, were prepared for sequencing using the CEQTM 8000 instrument. With the aim of analyzing the presence of type A mutation in NPM1 exon 12, an RT-ASO-PCR strategy was used. A forward primer was designed to specifically amplify NPM1 exon 12 only if the mutation A is present; this primer in fact contains an intentional mismatch at third nucleotide from 3’ end to improve specificity. The amplified region includes the insertion of a TCTG tetranucleotide and corresponds to a 320 bp amplified product. As internal PCR control the ABL housekeeping gene was also amplified in each sample. In order to increase the sensitivity for the assay for MRD monitoring, we set up a semi-nested ASO-PCR; for this purpose an internal forward primer NPM-AN for NPM1 mut-A was designed, corresponding to a 319 bp amplified fragment. Fragment analysis allowed to identify 17 NPM1m samples. All the NPM1m samples were heterozygous confirming that NPM1m allele is negative dominant. As concerning sensitivity method enabled to detect the NPM1 mutations present in concentration of 10-2. Sequencing analysis confirmed in all instances NPM1m and NPM1wt cases, showing that 12 samples harboured the most frequent type A mutation, the remaining mutated samples showing type B (3 cases), type D (1 case) and type K mutation (1 case). RT-ASO-PCR assay confirmed the capillary electrophoresis and sequencing results, showing a concordance in 100% of cases; in fact this method identified the 12 out of 17 NPM1m samples as NPM1 mut-A, with an overall frequency of 70%. The semi-nested ASO-PCR assay was carried out to increase the sensitivity of this assay for the monitoring of MRD. The sensitivity calculated for both methods, RT-ASO-PCR and semi-nested ASO-PCR, indicated that this assays could detect the NPM1 mut-A present in concentration of 10-2 and 10-5, respectively. Out of 107 patients, cytogenetic data were available for 99 patients, divided into 2 groups: a group (n=15) consisting of NPM1m and a group (n=84) with NPMwt. Twenty seven out of 99 had normal karyotype. Amongst twenty seven, 13 were NPM1m with an incidence of 48%. The capillary electrophoresis assay developed in this work proved to be a fast, reproducible and easy method applicable to NPM1m diagnosis, capable to discriminate 1 mutated cell out of 100. RT-ASO-PCR and the more sensitive semi-nested ASO-PCR were developed for specifically detect NPM1mut-A, the most frequent NPM1 mutation. These methods were capable to detect 1 mutated cell out of 100 and out of 100.000, respectively. Monitoring more patients by these new assays in MRD longitudinal studies could be relevant for better assess molecular remission and the risk of relapse in AML-NK.
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Lisi, Samuele. "Approches innovantes basées sur la Résonance des Plasmons de Surface pour le diagnostic biomoléculaire de la maladie d’Alzheimer." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAV003/document.

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La maladie d’Alzheimer est une pathologie neurodégénérative qui amène à une perte progressive de la mémoire et cause des changements comportementaux. Selon plusieurs théories, le développement de cette maladie est associé à l’accumulation du peptide amyloïde beta et de la protéine tau dans des zones précises du cerveau humain. A l’heure actuelle, les approches thérapeutiques testées sont fondées sur l’hypothèse de la cascade amyloïde, mais les résultats n’ont pas été jugés suffisamment efficaces. Pour augmenter les chances de succès des traitements thérapeutiques existants, de meilleures techniques pour un dépistage précoce de l’Alzheimer semblent nécessaires. De ce fait, dans cette thèse, des stratégies innovantes pour l’analyse d’un des biomarqueurs de la maladie d’Alzheimer sont proposées. En particulier le projet porte sur l’analyse de la protéine tau avec des biocapteurs basés sur la Résonance de Plasmons de Surface (SPR). L’augmentation du niveau de ce biomarqueur dans le Liquide Céphalo-Rachidien (LCR) est déjà indicateur d’un processus de neurodégénérescence. De plus, si la mesure de la protéine tau est combinée à celle d’autres biomarqueurs de la pathologie (i.e. : amyloïde beta), les possibilités de dépistage sont fortement augmentées. Les travaux ont portés sur deux aspects : initialement l’interaction antigène-anticorps a été exploitée pour développer un immunocapteur pour la protéine tau. En utilisant cette technologie, nous avons pu caractériser les paramètres analytiques de l’essai direct (avec un seul anticorps) et ceux de l’essai sandwich (avec deux anticorps complémentaires). Dès ces premières approches, nous avons remarqué le besoin d’augmenter la sensibilité de la méthode SPR développée. En effet la limite de détection pour l’essai sandwich était de l’ordre du nM, alors que les niveaux de tau dans le LCR sont de l’ordre du pM. L’utilisation de nanotechnologies, en particulier des nanotubes de carbone, a permis d’atteindre des niveaux proches du pM, avec de bonnes performances en terme de répétabilité de l’essai.Une approche alternative a été conçue dans la deuxième partie du projet. Elle était consacrée à la sélection d’un aptamère pour la protéine tau, afin d’exploiter les avantages de cette classe de récepteurs par rapport aux anticorps. Pour accomplir cet objectif, deux stratégies de sélection ont été mises en place. Premièrement la sélection traditionnelle (SELEX, Systematic Evolution of Ligands by EXponential enrichment) a été appliquée en utilisant l’Electrophorèse Capillaire (EC) comme moyen de séparation. Bien que de nombreuses conditions aient été modifiées, avec le SELEX traditionnel nous n’avons pas observé une évolution significative de l’affinité entre les séquences d’ADN et la protéine tau. Dans la deuxième approche nous avons utilisé la même méthode de séparation pour mener la sélection à travers l’EC-Non-SELEX. En utilisant cette méthode, où les étapes de PCR étaient réduites, une évolution positive a été observée après seulement trois rounds. En effet cinq séquences parmi celles issues du dernier round ont montré une affinité supérieure pour la cible par rapport à la banque. Néanmoins le nombre de séquences analysées à la fois par SPR et par anisotropie de fluorescence reste extrêmement limité par rapport au pool initial. Même si ceci semble être une limite, ce travail est le premier où les aptamères sont appliqués à l’analyse de la protéine tau. Le potentiel de cette classe de récepteurs reste en grande partie inexploré, ce qui laisse entrevoir des améliorations possibles de l’affinité grâce à de meilleurs processus de sélection et au développement de nouveaux outils bioinformatiques.En conclusion la SPR grâce à ses caractéristiques jouera un rôle fondamental dans les prochaines années pour l’analyse des biomarqueurs et pour le screening de nouvelles molécules, qui seront l’objet de futurs essais cliniques pour limiter l’agrégation de la protéine tau
Alzheimer’s disease (AD) is a widespread pathogenic condition causing memory and behavior impairment mostly in elderlies because of the accumulation of amyloid beta peptide and tau protein in human brain. Current therapeutic approaches, based on the amyloid hypothesis, are unable to arrest the progression of the disease, hence early diagnosis is crucial for an effective intervention. Based on the updated criteria for AD probable diagnosis, and considering the limits associated with the actual analytical techniques, my work in this thesis was dedicated to develop novel strategies for AD diagnosis. The whole project focused on the analysis of tau protein by Surface Plasmon Resonance (SPR) biosensing. Such protein is well known for being relevant as neurodegenerative marker. In particular if the measurement of tau is associated with that of the amyloid beta peptide and that of the phosphorylated tau, the clinical specificity of this protein become significant to detect Alzheimer. Two aspects were studied; first of all an immunosensor was developed taking advantage of the well-established antigen-antibody interaction. After characterization of the analytical parameters of the direct assay (with primary antibody), a sandwich assay (using two monoclonal antibodies mapping on different analyte i.e. protein tau epitopes) was developed, allowing very low sensitivity to be obtained in artificial Cerebrospinal Fluid (aCSF). In particular to enhance the analytical signal Carbon Nano Tubes (CNTs) were used. Secondly, the research was focused on the selection of aptamers for tau. To this aim two SELEX (Systematic Evolution of Ligands by EXponential enrichment) methods were compared, both based on Capillary Electrophoresis (CE) for partitioning step of the process. Whether with CE-SELEX (first method), no significant affinity improvement was measured, using the CE-Non-SELEX (second method) affinity of the DNA library for tau protein was consistently improved. After isolation of a limited population of aptamer candidates, five sequences were chosen to be analyzed for their affinity for the target. Fluorescence Anisotropy (FA) measurements and SPR highlight similar behavior for the selected sequences, despite the detection principles of these techniques are significantly different. In conclusion the work highlight versatility of SPR technology used both for quantitative analysis and for new selected aptamers characterization in terms of affinity for the analyte tau. The above mentioned versatility is of great interest in a field such AD, which is rapidly expanding. Lowering the total tau levels has been recently identified as a new goal for therapy. Therefore many drug candidates are likely going to be tested in the near future. SPR technology is already widely used in pharmaceutical industry to investigate novel molecules, since it gives access to a large panel of information. In this panorama aptamer technology may improve the overall quality of the analytical data, allowing better comparison among drug candidates. With respect of these receptors, the thesis opened the door to new studies for DNA aptamers to recognize tau, with considerable advantages in term of the receptor stability. Moreover the whole potential of DNA aptamers selected in this work still remain to be explored. New selection methodologies, combined with fast progression of bioinformatics tools might give rise to affinity improvement, which will lead to sensitivity improvement for tau detection in the next few years
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LUCARELLI, CLAUDIA. "La multiresistenza in Salmonella: caratterizzazione molecolare di un nuovo clone emergente di Salmonella enterica sierotipo Typhimurium." Doctoral thesis, Università degli Studi di Roma "Tor Vergata", 2009. http://hdl.handle.net/2108/1089.

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Salmonella enterica sierotipo Typhimurium (STM) rappresenta la prevalente causa di gastroenterite trasmessa da alimenti in Italia, con la maggior parte degli isolati con resistenza multipla agli antibiotici, principalmente ad ampicillina (A), cloramfenicolo (C), streptomicina (S), sulfamidici (Su) e tetraciclina (T) (ACSSuT). Un nuovo pattern di resistenza (R-type) ASSuT, mancante della resistenza a C, è recentemente emerso in Italia tra ceppi di STM e della sua variante monofasica, Salmonella enterica subspecie enterica sierotipo S. 4,[5],12:i:– . L’obiettivo principale di questa tesi è stato la caratterizzazione di ceppi di STM e di S. 4,[5],12:i:– con R-type ASSuT, usando tecniche di tipizzazione molecolari e fenotipiche, quali l’elettroforesi in campo pulsato (PFGE) e la fagotipizzazione, allo scopo di valutare la loro origine clonale e la loro relazione con i ceppi ACSSuT. Usando il database Pulse-Net Europe è stata valutata la presenza di ceppi ASSuT in altre nazioni Europee al fine di allestire una collezione internazionale di ceppi. Questa collezione è stata ulteriormente caratterizzata, identificando i geni di resistenza, investigando la loro localizzazione, e determinando la regione di resistenza. Sia tra ceppi di STM che di S. 4,[5],12:i:–, il principale profilo di PFGE è rappresentato da STYMXB.0079, mentre i ceppi STM ACSSuT appartengono ai profili STYMXB.0061 e STYMXB.0067. L’analisi dei profili di PFGE con il software Bionumerics ha mostrato che più del 90% dei ceppi ASSuT e ACSSuT appartenevano a due distinti clusters con un’omologia genetica del 73%, dati che dimostrano l’appartenenza dei ceppi ASSuT ad un'unica linea clonale differente da quella dei ceppi ACSSuT. La maggior parte dei ceppi con profilo ASSuT non erano tipizzabili (DTNT) attraverso la fagotipizzazione o appartenevano al fagotipo U302. Al contrario i ceppi ACSSuT appartenevano principalmente al fagotipo DT104. Successivamente, nel database Pulse-Net Europe, è stato possibile identificare ceppi ASSuT, sia STM che S. 4,[5],12:i:– isolati in Danimarca ed Inghilterra, con profili di PFGE identici o strettamente correlati a quelli dei ceppi italiani, dati che indicano che il clone ASSuT è presente anche in altri paesi Europei. Al fine di identificare i geni responsabili della resistenza sono stati selezionati 64 ceppi di STM e S. 4,[5],12:i:– ASSuT, e 11 ceppi di STM con differenti R-type e profili di PFGE, usati come controlli. Tutti i ceppi provenivano da infezioni umane ed erano stati isolati in Italia, Danimarca e Inghilterra. Tutti i ceppi ASSuT erano positivi per i seguenti geni di resistenza: blaTEM, strA-strB, sul2 and tet(B). Successivi esperimenti di localizzazione hanno dimostrato che i geni di resistenza ASSuT sono localizzati sul cromosoma Infine, è stata determinata la sequenza completa del cluster di resistenza ASSuT. Questo cluster è composto da due isole di resistenza (RI1 e RI2) separate da DNA cromosomale. In particolare, RI1 è compresa tra due IS26 e contiene deltatnp3R, blaTEM-1, tnpB, seguito da strB, strA, sul2, repC, deltarepA ed un’atra IS26. RI2 è anch’essa compresa tra due IS26, comprendenti deltaIS10L, il gene di resistenza alla tetraciclina, IS1, l’operone per la resistenza al mercurio, il gene yaeA, e un’ ipotetica transposasi (tniAdelta). Entrambe le RIs mostrano il 99% di identità con due regioni adiacenti del plasmide pHCM1, presente nel ceppo di S. Typhi isolato in Vietnam. Le sequenze di inserzione IS26 potrebbero aver avuto un ruolo nella formazione di questo cluster di resistenza, ma quest’ipotesi deve essere ancora verificata. In conclusione il lavoro di questa tesi indica che i ceppi ASSuT di STM e S. 4,[5],12:i:–, in aumento in Italia, appartengono ad un'unica linea clonale e che i ceppi S. 4,[5],12:i:– circolanti nella nostra nazione, derivano principalmente da questa linea clonale di STM. Inoltre il clone ASSuT è diffuso anche in Danimarca ed Inghilterra. Il pattern di antibiotico resistenza conferito da un’isola di resistenza cromosomale, con un’organizzazione simile ad altri cluster precedentemente descritti, suscita preoccupazione poichè la resistenza può essere mantenuta stabilmente in assenza di pressione selettiva.
Salmonella enterica serovar Typhimurium (STM) represents the prevalent cause of foodborne gastroenteritis in Italy with the majority of isolates exhibiting multidrug resistance, mainly to ampicillin (A), chloramphenicol (C), streptomycin (S), sulfonamide (Su) and tetracycline (T) (ACSSuT). However, a new resistance pattern (R-type) ASSuT, lacking resistance to C, has recently emerged in Italy among strains of STM and of its monophasic variant, Salmonella enterica subspecie enterica serovar S. 4,[5],12:i:– . The main objective of this thesis has been the characterization of STM and S. 4,[5],12:i:– strains with R-type ASSuT, using both molecular and phenotypic typing technique, pulsed-field gel electrophoresis (PFGE) and phage typing, in order to evaluate their clonal origin and the relationships with the ACSSuT strains. In addition, by the use of the Pulse-Net database it was evaluated if ASSuT strains were present in other European countries in order to set up an international collection of these strains. This collection has been further characterized with the identification of resistance genes, the investigation of their localization, and determination of the resistance region. Among both the STM and S. 4,[5],12:i:– ASSuT strains, the predominant PFGE profile was STYMXB.0079, while the STM ACSSuT strains belonged to the STYMXB.0061 and STYMXB. 0067. Bionumerics cluster analysis of PFGE profiles showed that more than 90% of ASSuT and ACSSuT resistant strains were included in two distinct clusters with a genetic homology of 73% each other, suggesting that the ASSuT resistant strains belong to a same clonal lineage different from that of the ACSSuT strains. Phage typing showed that both STM and S. 4,[5],12:i:– ASSuT strains were not typeable (DTNT) or U302. A different figure was observed for the ACSSuT strains: the STM strains mostly belonged to DT104. The Pulse-Net Europe database, allowed us to identify ASSuT strains, both STM and S. enterica 4,[5],12:i:–, isolated in Denmark and UK, with the same or very closely related PFGE patterns as the Italian strains, suggesting that the ASSuT clone is circulating in different European countries. The resistance genes were identified in 64 strains of STM and S. enterica 4,[5],12:i:–with ASSuT R-type and in 11 STM strains with different resistance patterns and PFGE profiles as controls. All strains were isolated from human infections in Italy, Denmark and UK. All the ASSuT strains were positive for the following resistance genes: blaTEM, strA-strB, sul2 and tet(B). The control strains showed the same gene pattern, in accordance with their resistance profiles. A variability of the genes conferring resistance to tetracycline was detected. Localization experiments demonstrated that the ASSuT resistance genes are chromosomally located. Finally, the complete sequence of ASSuT resistance cluster was determined. This cluster is composed by two resistance island (RI1 and RI2) divided by chromosomal DNA. In particular, RI1 is comprised between two IS26 and contains deltatnp3R, blaTEM-1, tnpB , followed by strB, strA, sul2, repC, DeltarepA and another IS26. RI2 is bracketed by two IS26, comprising deltaIS10L, tetracycline resistance gene, IS1, the operon for resistance to mercury, yaeA gene, and a putative transposase (tniAdelta). Both this RIs show 99% sequence identity to two adiacent region of pHCM1 plasmid, harbored in S. Typhi isolated in Vietnam. IS26 elements could have played a role in the assembly of this resistance cluster but it will be investigated more in detail. In conclusion the work of this thesis indicates that the tetra-resistant ASSuT strains of STM and S. 4,[5],12:i:–, increasingly isolated in Italy, belong to a same clonal lineage and that the S. 4,[5],12:i:– strains circulating in our country, mainly derive from this STM clonal lineage. ASSuT clone is also circulating in Denmark and United Kingdom. The antimicrobial resistance pattern conferred by a chromosomal island, with an organization similar to previously reported clusters, deserves concern since the resistance could be stably maintained even in the absence of selective pressure.
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Khalifeh, Iman. "Determination of self association constant between bovine insulin molecules by capillary zone electrophoresis." Thesis, Uppsala University, Department of Medical Biochemistry and Microbiology, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-6155.

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Capillary electrophoresis (CE) is an analytical technique that is very useful for investigating processes that modify the charge and mass of proteins and polypeptide pharmaceuticals. This report explores the ability of CE to determine the aggregation constant between insulin molecules. Bovine insulin is a polypeptide (Mw=5733, pI = 5.3) that has two α-amino groups (Gly and Phe) and one ε–amino group (Lys). Analysis of concentration dependence of electrophoretic mobility of insulin at different conditions yields the association constant for dimerization of insulin. The association constant estimates how tight the peptide molecules are associated. The association constant is a useful factor to evaluate the purity of a peptide or protein sample.

The association reaction of bovine insulin molecules was found to be favoured by temperature. The association constants were 7200 M -1, 8000 M -1, and 36000 M -1 at 15 oC, 25 oC and 35 oC, respectively. The interactions between the peptide molecules increase at higher temperature, resulting in stronger association. The association constant was estimated to be 3000 M -1in the presence of dioxane (5%, w/v %) at 25 oC. However, the interaction sites remain to be explored.

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Vuorensola, Katariina. "Capillary electrophoresis and capillary electrophoresis-mass spectrometry in catecholamine studies." Helsinki : University of Helsinki, 2002. http://ethesis.helsinki.fi/julkaisut/mat/kemia/vk/vuorensola/.

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Renard, Charly. "Nouvelles approches pour la quantification et la réduction de l’adsorption de biomolécules en électrophorèse capillaire : capillaires superhydrophobes et multicouches de polyélectrolytes." Thesis, Montpellier, 2020. http://www.theses.fr/2020MONTS013.

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L’objectif de cette thèse est d’étudier différentes approches pour la modification de la paroi interne des capillaires d’électrophorèse capillaire pour améliorer les efficacités de séparation de biomolécules (peptides et/ou protéines modèles) en milieu acide. Le premier chapitre (hors étude bibliographique) est consacré à l’étude des revêtements superhydrophobes, dans le but d’empêcher l’adsorption des analytes en supprimant toute interaction entre la paroi superhydrophobe et les analytes (absence de mouillage). Un protocole de greffage original a été développé pour obtenir des capillaires superhydrophobes en étudiant l’influence du nombre de couches déposées, la nature du revêtement, et les pressions de remplissage et de rinçage du capillaire lors du dépôt des couches. Des capillaires superhydrophobes ont pu être obtenus, pour la première fois, avec des diamètres internes allant de 50 µm à 180 µm. Les caractéristiques hydrodynamiques et électrocinétiques de ces capillaires ont été étudiées, donnant une longueur de glissement de 23 µm et des efficacités de séparation électrophorétique 2 fois supérieures à celles obtenues sur un capillaire de silice vierge dans les mêmes conditions électrophorétiques. Le second chapitre étudie la génération de microbulles d’air dans des capillaires superhydrophobes. ). Les paramètres expérimentaux (tension, rayonnement UV, marqueur, revêtement superhydrophobe) nécessaires à l’obtention de ces microbulles ont été identifiés). Ces bulles ont été caractérisées (diamètre ~35-39 µm ; longueur ~10 mm ; potentiel zeta ~ -62.6 mV). Le troisième chapitre propose une méthodologie expérimentale, basée sur la théorie de l’électrochromatographie, permettant d’évaluer l’adsorption résiduelle de protéines sur la paroi des capillaires. Cette nouvelle approche présente deux intérêts : (i) pouvoir comparer les performances séparatives sur différents greffages via l’adsorption résiduelle, et (ii) optimiser les paramètres expérimentaux (longueur, diamètre interne, tension appliquée) afin de minimiser l’impact de l’adsorption sur les efficacités de séparation
The main objective of this thesis is to study different approaches for the modification of the electrophoresis capillary intern wall to enhance separation efficiency and reproducibility for biomolecules (model peptides and/or proteins) in acidic conditions. The first chapter (outside of bibliographic study) is dedicated to superhydrophobic coatings study. The goal is to prevent analytes adsorption by suppressing any interaction between the superhydrophobic wall and the analytes (anti-wettability). An original coating process has been developed to obtain superhydrophobic capillaries by studying the influence of layers number, coating nature, and filling and flushing pressure during layers deposition. Superhydrophobic coatings have been obtained, for the first time, with diameters from 50 µm to 180 µm. Hydrodynamic and electrokinetic characteristics have been studied, giving slipping length of 23 µm and efficiency separation increased twofold compared to fused silica capillary in the same electrophoretic conditions. The second chapter studies an air microbubbles generation process using superhydrophobic capillaries. The experimental parameters (voltage, UV ray, marker, superhydrophobic coating) needed to obtain those bubbles have been identified. Those bubbles have been characterized (diameter ~35-39 µm; length ~10 mm; zeta potential ~ -62.6 mV). The third chapter offer an experimental methodology, based on the electrochromatography theory, allowing to evaluate the residual adsorption of proteins on the capillary wall. This approach have two interesting points: (i) allowing to compare separative performances of different coatings via residual adsorption, and (ii) optimizing the experimental parameters (length, internal diameter, applied voltage) to minimize the impact of adsorption on the separation efficiencies
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Baratuci, William Brian. "Counteracting flow electrophoresis." Case Western Reserve University School of Graduate Studies / OhioLINK, 1991. http://rave.ohiolink.edu/etdc/view?acc_num=case1055352218.

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Ruel, Coralie. "Apport de l'électrophorèse capillaire pour l'étude des anomalies de glycosylation de protéines liées à des pathologies : vers l'identification de nouveaux biomarqueurs." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLS519.

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La glycosylation est l’une des principales modifications post-traductionnelles des protéines. La glycosylation des protéines est fortement modifiée lors de diverses pathologies comme le cancer, la polyarthrite rhumatoïde ou les troubles congénitaux de la glycosylation («Congenital disorders of glycosylation», CDGs). Ainsi, la nature et les proportions relatives des oligosaccharides liés aux protéines peuvent être utilisées pour dépister, pronostiquer voire suivre l’évolution de pathologies. Les travaux de cette thèse se sont focalisés sur l’étude de la glycosylation pour permettre le dépistage de certaines pathologies : les CDGs, la maladie d’Alzheimer (MA) et la dégénérescence rétinienne. Plusieurs stratégies fondées sur l’électrophorèse capillaire (EC) ont été envisagées pour répondre à cet objectif. Tout d’abord, le développement d’une méthode par EC de zone (ECZ) l’apolipoprotéine C-III (ApoC-III) intacte, une O-glycoprotéine impliquée dans le dépistage des troubles de la O-glycosylation, a permis de séparer les différentes glycoformes selon leur degré de sialylation. L’analyse d’échantillons d’ApoC-III standard provenant de différents fournisseurs par spectrométrie de masse (MS) MALDI -TOF a mis en évidence une hétérogénéité liée à la présence (inattendue) de formes carbamylées. Un traitement du plasma basé sur une immunocapture de l’ApoC-III suivie d’une dérivation sur billes magnétiques de la protéine par un fluorophore a permis de séparer ses différentes glycoformes en ECZ. Ensuite, une analyse N-glycomique de fluides biologiques employant une nouvelle technique de préparation d’échantillon que nous avons adaptée au plasma et au liquide céphalorachidien, a été réalisée par EC en gel couplée à une détection par fluorescence induite par laser (ECG-LIF) sur des patients sains et atteints de la MA. Cette étude a permis de mettre en évidence quelques modifications des N-glycanes chez ces patients. Enfin la combinaison des deux stratégies d’analyse de la glycosylation (glycoprotéine intacte et glycanes libérés), a permis de détecter la transferrine intacte présente dans le liquide vitré à des concentrations faibles ainsi que ses N-glycanes libérés, dans le cadre du dépistage d’une maladie oculaire. L’EC-QTOF-MS a également été explorée pour l’analyse de N-glycanes dérivés avec un nouveau fluorophore permettant d’améliorer la sensibilité en MS
Glycosylation is one of the most main types of post-translational modifications of proteins. Disease-associated modifications in protein glycosylation have been observed for various pathologies such as cancer, rheumatoid arthritis, or «Congenital disorders of glycosylation» (CDGs). They are often exploited for diagnosis, prognosis and monitoring of these diseases. This thesis work focused on the glycosylation study with the aim to allow the screening of different pathologies: CDGs, Alzheimer’s disease and retinal degeneration diseases. Different strategies based on capillary electrophoresis (CE) were considered to fulfil this goal. First, the developement of a CZE analysis of intact apolipoprotein C-III (ApoC-III), an O-glycoprotein implied in the screening of O-glycosylation disorders, allowed the separation of its glycoforms according to their sialylation degree. The MALDI-TOF mass spectrometry (MS) analysis of standard ApoC-III batches from different standard ApoC-III batches from different suppliers highlighted an additonnal heterogeneity due to (unexpected) carbamylated species. A plasma pretreatment based on an immunocapture of apoC-III followed by protein derivatization on magnetic beads using a fluorophore allowed to separate its glycoforms by CZE. Second, a glycomic analysis of biologicial fluids using a new sample treatment method that we adjusted to plasma and cerebrospinal fluid samples was performed by CGE-LIF on controls and Alzheimer’s patients. It allowed to highlight some modifications of N-glycans for this disease. Finally, the combination of both strategies of glycosylation analysis (intact glycoprotein and released N-glycans) allowed the detection of intact transferrin present in vitrous humor but also of its released N-glycans for the screening of retinal degeneration disease. CE-QTOF-MS was also investigated for the analysis of released N-glycans derivatized by a new fluorophore which increases MS sensitivity
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Books on the topic "Electrophoresi"

1

Li, S. F. Y. Capillary electrophoresis: Principles, practice, and applications. Amsterdam: Elsevier, 1992.

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Baker, Dale R. Capillary electrophoresis. New York: Wiley, 1995.

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Practical capillary electrophoresis. Boston: Academic Press, 1993.

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Practical capillary electrophoresis. 2nd ed. San diego, CA: Academic Press, 2000.

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1941-, Bauer Johann, ed. Cell electrophoresis. Boca Raton: CRC Press, 1994.

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Mosher, R. A. The dynamics of electrophoresis. Weinheim: VCH, 1992.

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Margit, Burmeister, and Ulanovsky Levy, eds. Pulsed-field gel electrophoresis. Totowa, N.J: Humana Press, 1992.

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Hawcroft, David M. Electrophoresis. Oxford: IRL Press at Oxford University Press, 1997.

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Melvin, Maureen. Electrophoresis. Edited by Kealey D and ACOL (Project). Chichester [West Sussex]: Published on behalf of ACOL, London, by Wiley, 1987.

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Two-dimensional electrophoresis, and immunological techniques. New York: Plenum Press, 1987.

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Book chapters on the topic "Electrophoresi"

1

Agrawal, Sarita, and Shubhra Malviya. "Allozyme Diversity Inforensically Important Indian Species Chrysomya Megacephala (Fabricius) (Diptera: Calliphoridae)." In Proceedings of the Conference BioSangam 2022: Emerging Trends in Biotechnology (BIOSANGAM 2022), 225–34. Dordrecht: Atlantis Press International BV, 2022. http://dx.doi.org/10.2991/978-94-6463-020-6_22.

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AbstractThe application of electrophoretic technique to study allozyme enzymatic variation has been extensively used to explore hidden genetic variability in natural population and laboratory colonies of many calliphorid flies. Genetic variation at three enzyme loci viz., Alkaline phosphatase (APH), Xanthin dehydrogenase(XDH)and Malate dehydrogenase (MDH) in laboratory colonies of Chrysomya megacephalawere investigated by using polyacrylamide gel electrophoresis (PAGE). In APH three zones of activity were observed. Which have been designated as APH-1, APH-2, and APH-3 in order of increasing anodal migration. The electrophoretic phenotypes with two codominant alleles were observed at APH-3loci. In MDH and XDH only one zone of activity was observed.
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Vojtíšková, Marie. "Electrophoresis." In Experimental Techniques in Bioelectrochemistry, 489–526. Basel: Birkhäuser Basel, 1995. http://dx.doi.org/10.1007/978-3-0348-7607-0_8.

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Dorfman, Kevin D. "Electrophoresis." In Encyclopedia of Microfluidics and Nanofluidics, 926–34. New York, NY: Springer New York, 2015. http://dx.doi.org/10.1007/978-1-4614-5491-5_453.

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Buxbaum, Engelbert. "Electrophoresis." In Biophysical Chemistry of Proteins, 61–95. Boston, MA: Springer US, 2010. http://dx.doi.org/10.1007/978-1-4419-7251-4_8.

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Pomeranz, Yeshajahu, and Clifton E. Meloan. "Electrophoresis." In Food Analysis, 208–27. Boston, MA: Springer US, 1994. http://dx.doi.org/10.1007/978-1-4615-6998-5_15.

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Gordon, M. H., and R. Macrae. "Electrophoresis." In Instrumental Analysis in the Biological Sciences, 67–82. Boston, MA: Springer US, 1987. http://dx.doi.org/10.1007/978-1-4684-1521-6_4.

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Dennison, Clive. "Electrophoresis." In A Guide to Protein Isolation, 139–77. Dordrecht: Springer Netherlands, 2003. http://dx.doi.org/10.1007/978-94-017-0269-0_6.

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Kish, Adrienne. "Electrophoresis." In Encyclopedia of Astrobiology, 718–19. Berlin, Heidelberg: Springer Berlin Heidelberg, 2015. http://dx.doi.org/10.1007/978-3-662-44185-5_500.

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Charcosset, Catherine. "Electrophoresis." In Encyclopedia of Membranes, 655–56. Berlin, Heidelberg: Springer Berlin Heidelberg, 2016. http://dx.doi.org/10.1007/978-3-662-44324-8_206.

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Dorfman, Kevin D. "Electrophoresis." In Encyclopedia of Microfluidics and Nanofluidics, 1–12. Boston, MA: Springer US, 2013. http://dx.doi.org/10.1007/978-3-642-27758-0_453-2.

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Conference papers on the topic "Electrophoresi"

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Ohara, T., and A. Majumdar. "Ratcheting Electrophoresis Microchip (REM) for Programmable Transport and Separation of Macromolecules." In ASME 2001 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2001. http://dx.doi.org/10.1115/imece2001/mems-23888.

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Abstract This paper introduces the concept of a ratcheting electrophoresis microchip (REM), a microfluidic device for electrophoretic separation of macromolecules such as DNA and proteins in aqueous solution using low applied voltages (∼ 1 V). The device consists of several thousands of parallel linear electrodes with a constant pitch of about 10 μm. A spatial saw-tooth like potential distribution generated by the electrode array causes local electrophoretic migration of charged molecules between adjacent electrodes. By cycling the potential distribution in a certain pattern, the spatio-temporal electrophoretic ratchet can be used to separate and manipulate macromolecules at speeds much faster than thermal ratchets or more traditional techniques such as capillary or gel electrophoresis. This paper describes results of two simulations: First, using a simple one-dimensional potential distribution for the ratchet, the basic device function is examined using a probabilistic approach that simulates the interplay between electrophoretic mobility and molecular diffusion. The results suggest that the REM can function as a molecular filter through which only molecules having mobility larger than a threshold can pass. The REM can also be programmed to separate molecules to create a molecular profile, much like conventional electrophoresis. Second, two-dimensional stochastic simulations based on molecular diffusion and transient Debye screening by mobile ions are used to demonstrate the feasibility of the REM. The results suggest that biomolecular separation can indeed be achieved within time and length scales much shorter than capillary and gel electrophoresis.
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David, Regis A., Justin L. Black, Brian D. Jensen, and Sandra H. Burnett. "Modeling and Experimental Validation of DNA Motion During Electrophoresis." In ASME 2010 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/detc2010-28541.

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This paper describes the protocol and presents the results for DNA motion experiments using fabricated macroscale gel electrophoresis devices. Gel electrophoresis is a process used to separate/move DNA, RNA or protein molecules using an electric field through a gel matrix (electrolytic solution). In electrolytic solutions, the current conduction is due to a transport of ions (anions and cations). A better understanding of electrophoretic fundamentals allows for modeling the motion of DNA during electrophoresis. The model is validated through comparison with the experimental results. The model and experimental validation will be used to improve the process of cellular nanoinjection of DNA, currently in development in our lab.
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Cui, Huanchun, Prashanta Dutta, and Cornelius F. Ivory. "An Automated Valve for Dispersion Control in On-Chip Electrophoresis." In ASME 2007 International Mechanical Engineering Congress and Exposition. ASMEDC, 2007. http://dx.doi.org/10.1115/imece2007-41332.

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Band dispersion and sample loss into a side channel is a major problem when an electrokinetically-mobilized concentration zone passes a T-junction in a networked microfluidic chip. The band dispersion can be minimized in linear electrophoretic systems such as zone electrophoresis and moving boundary electrophoresis by applying a constant additional electric field in the side channel. However, constant valve voltages have shown to provide unsatisfactory valve performance during nonlinear electrophoresis (isotachophoresis). In this study, an automated valve system was developed to reduce the band dispersion at the intersection during non-linear electrophoresis. The automated valve consists of two integrated microelectrodes and a control system. With the automated control system, two integrated microelectrodes provide an effective way to manipulate current streamlines, thus acting as a non-mechanical valve for charged species in electrokinetic separations. Experimental results with this non-mechanical valve show decreased dispersion and increased reproducibility as protein zones isotachophoretically passed the T-junction.
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Lin, David C., Noshir A. Langrana, and Bernard Yurke. "The Migration of DNA Into a DNA-Crosslinked Gel Using Electrophoresis." In ASME 2003 International Mechanical Engineering Congress and Exposition. ASMEDC, 2003. http://dx.doi.org/10.1115/imece2003-43446.

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DNA-crosslinked polyacrylamide gels are polymeric electrolytes by virtue of the fact that DNA is negatively charged in an aqueous solution. As such, their mechanical properties can be altered by electrophoretic and electro-osmotic effects. Hybridization of single-stranded DNA with single-stranded sections of the crosslinks provides a novel means of altering gel mechanical properties. As a step toward exploring this means of altering gel mechanical properties, we report here on a study of the use of electrophoresis to introduce single stranded DNA into DNA crosslinked gels. Changes in elastic properties of the gel, before and after electrophoresis, were measured.
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Giridharan, M. G., and Anantha Krishnan. "An Implicit Numerical Model for Electrophoretic Systems." In ASME 1998 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 1998. http://dx.doi.org/10.1115/imece1998-1223.

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Abstract An implicit finite-volume approach has been developed to solve the equations governing the electrophoretic process. The numerical procedure involves the sequential solution of the species conservation ionization equilibria and electro-neutrality equations in an iterative fashion until convergence. This implicit procedure is numerically stable and allows for faster steady-state solutions or larger time steps for time-accurate simulations. Temporal evolutions of pH, species concentrations and electrolyte conductivity are predicted. The results obtained using various higher order numerical schemes are compared and assessed. Results are presented for the isoelectric focussing, moving boundary electrophoresis, and capillary electrophoresis of amino acids and a protein. The predictions for the isoelectric focussing of albumin protein are in qualitative agreement with published experimental data.
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6

Wang, Yi, Qiao Lin, and Tamal Mukherjee. "Models for Joule Heating Dispersion in Complex Electrophoretic Separation Microchannels." In ASME 2004 International Mechanical Engineering Congress and Exposition. ASMEDC, 2004. http://dx.doi.org/10.1115/imece2004-60970.

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This paper presents an analytical and parameterized model for analyzing the effects of Joule heating on analyte dispersion in electrophoretic separation microchannels. We first obtain non-uniform temperature distributions in the channel resulting from Joule heating, and then determine variations in electrophoretic velocity, based on the fact that the analyte’s electrophoretic mobility depends on the buffer viscosity and hence temperature. The convection-diffusion equation is then formulated and solved in terms of spatial moments of the analyte concentration. The resulting model is validated by both numerical simulations and experimental data, and holds for all mass transfer regimes, including unsteady dispersion processes that commonly occur in microchip electrophoresis. This model, which is given in terms of analytical expressions and fully parameterized with channel dimensions and material properties, applies to dispersion of analyte bands of general initial shape in straight and constant-radius-turn channels. As such, the model can be used to represent analyte dispersion in microchannels of more general shape, such as serpentine- or spiral-shaped channels.
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Yap, Y. F., J. C. Chai, T. N. Wong, N. T. Nguyen, K. C. Toh, and H. Y. Zheng. "Electrophoretic Motion of Particles in a Microsystem." In ASME 2006 International Mechanical Engineering Congress and Exposition. ASMEDC, 2006. http://dx.doi.org/10.1115/imece2006-14121.

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Electrophoresis is the motion of a charged particle relative to the surrounding liquid due to an imposed external electric field1. Its applications include but are not limited to characterization and manipulation of organic and inorganic particles. In particular, electrophoresis has been applied to a variety of analytical separation problems involving nucleic acids, proteins and drugs. For electrophoresis on various Lab-on-a-chip platforms, the particles are of sizes comparable to the microchannel in which they flow. As such, particle-particle and particle-wall interactions are no longer negligible. Therefore, the electric field, the flow field and the particles motion are strongly coupled together. Numerical models based on a moving-grid method2 have been employed to investigate the related phenomena. Mesh regeneration as the particles move is an extra computational complication. To circumvent the complexity of mesh regeneration, a level-set based fixed-grid method3 is presented for electrophoretic motion of particles in this article. The particles are assumed to be a highly viscous liquid constraint to move with rigid body motion. A distance function is employed to represent the liquid-particle interfaces. The electric field, the flow field and the particles motion are governed respectively by the Poisson, the Navier-Stokes and the Euler-Newton equations. The effect of the electric field on the particle motion is accounted for by incorporating slip boundary conditions on the particles surfaces. The nonlinear governing equations are discretized and solved using a finite volume method4. The model is used to investigate electrophoretic motion of non-conducting circular and elliptical particles in a microsystem. Figure 1 shows the electrophoretic motion of a single circular particle in a microchannel. The induced electroosmotic flow is from the left to the right. The thick circles are the particle at t = 0. The direction of the particle movement is indicated by the arrows. The motions of the particle if neutral, positively or negatively charged are obviously different. Basically, a positively charged particle move faster than the main flow. However, a negatively charged particle flows slower. When the particle is highly charged negative, it can even flow against the streamwise direction toward upstream (+V) as in Fig. 1c. This suggests that there would be a situation where the particle can be kept static. Figure 2 shows the electrophoretic motion of multiple particles. The initial locations of the particles are shown in Fig. 2a. In the case of charged particles, particle 1, 2 and 3 are respectively negatively, neutral and positively charged. Particle 1 which is elliptical undergoes obvious rotational motion when charged (Fig. 2c). The case of the neutral particles (Fig. 2b) is included for comparison.
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8

RICHMAN, DAVID. "Microgravity electrophoresis." In 26th Aerospace Sciences Meeting. Reston, Virigina: American Institute of Aeronautics and Astronautics, 1988. http://dx.doi.org/10.2514/6.1988-71.

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9

Cantor, Charles R., and Hwa A. Lim. "The First International Conference on Electrophoresis, Supercomputing and the Human Genome." In The First International Conference on Electrophoresis, Supercomputing and the Human Genome. WORLD SCIENTIFIC, 1991. http://dx.doi.org/10.1142/9789814540278.

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10

Pennathur, Sumita, Fabio Baldessari, Mike Kattah, Paul J. Utz, and Juan G. Santiago. "Electrophoresis in Nanochannels." In ASME 2006 2nd Joint U.S.-European Fluids Engineering Summer Meeting Collocated With the 14th International Conference on Nuclear Engineering. ASMEDC, 2006. http://dx.doi.org/10.1115/fedsm2006-98558.

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Micro- and nanofabrication technology enables the application of electrokinetics as a method of performing chemical analyses and achieving liquid pumping in electronically-controlled microchip systems with no moving parts. We are studying and leveraging the unique separation modalities offered by nanoscale electrokinetic channels. We report analytical, numerical, and experimental investigations of nanochannel electrophoretic transport and separation dynamics of neutral and charged analytes. Our study includes continuum-theory-based analytical and numerical studies of nanofluidic electrophoretic separation dynamics, as well as experimental validation of these models. We have used 40, 100, and 1,560 nm deep channels etched in fused silica to independently measure mobility and valence of small ions. We also use these devices to separate 10 to 100 base pair DNA in the absence of a gel separation matrix. The effective free-solution mobilities of the ds-DNA oligonucleotides measured in 1560 nm deep channel are consistent with reported literature values, while smaller values of the mobility were measured for 4o nm deep channels for the same charge-species. The goal of our work is to explore and exploit electrokinetic flow regimes with extreme scales of length and charge density.
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Reports on the topic "Electrophoresi"

1

RAFAILOVICH, MIRIAM, JONATHAN SOKOLOV, and DILIP GERSAPPE. DNA ELECTROPHORESIS AT SURFACES. Office of Scientific and Technical Information (OSTI), September 2003. http://dx.doi.org/10.2172/900195.

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2

Xu, Aoshuang. Development in electrophoresis: instrumentation for two-dimensional gel electrophoresis of protein separation and application of capillary electrophoresis in micro-bioanalysis. Office of Scientific and Technical Information (OSTI), January 2008. http://dx.doi.org/10.2172/1342558.

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3

Sepaniak, M. J. Capillary Electrophoresis - Optical Detection Systems. Office of Scientific and Technical Information (OSTI), August 2001. http://dx.doi.org/10.2172/836641.

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4

Castro, A., and E. B. Shera. Single-molecule electrophoresis. Final report. Office of Scientific and Technical Information (OSTI), May 1996. http://dx.doi.org/10.2172/272560.

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Zhang, N. DNA typing by capillary electrophoresis. Office of Scientific and Technical Information (OSTI), October 1997. http://dx.doi.org/10.2172/587953.

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Dr. Barry Karger. DNA Sequencing Using capillary Electrophoresis. Office of Scientific and Technical Information (OSTI), May 2011. http://dx.doi.org/10.2172/1013010.

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Ballou, N. E., S. L. Petersen, G. R. Ducatte, and V. T. Remcho. Particle separations by electrophoretic techniques. Office of Scientific and Technical Information (OSTI), March 1996. http://dx.doi.org/10.2172/207057.

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8

Tollaksen, S. L., and C. S. Giometti. Procedures for two-dimensional electrophoresis of proteins. Office of Scientific and Technical Information (OSTI), October 1996. http://dx.doi.org/10.2172/505307.

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Xue, Yongjun. Novel absorption detection techniques for capillary electrophoresis. Office of Scientific and Technical Information (OSTI), July 1994. http://dx.doi.org/10.2172/10190663.

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Dorsey, John G. Octanol-Water Partition Coefficients by Capillary Electrophoresis. Fort Belvoir, VA: Defense Technical Information Center, January 1996. http://dx.doi.org/10.21236/ada335729.

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