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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Immunoassays or LC-MS/MS? : A Comparison Revealing the Properties of Modern Methods for Insulin, Pro-insulin, C-peptide and Glucagon Quantification

Upite, Ruta, Wärmegård, Susanna, Tiger, Casper, Ivert Nordén, Anna, Martinez, Temis, Umenius, Viktor January 2019 (has links)
The purpose of this report is to compare seven different methods for biomarker detection and quantification based on previously published papers. The methods investigated are ELISA, LC-MS/MS, UPLC-MS/MS, LC-IM/MS, IA-LC-MS/MS, MSIA-HR/AM, HTRF and AlphaLISA ® . The focus lies on biomarkers relevant for diabetes, obesity and cardiovascular diseases.Namely insulin, proinsulin, glucagon and C-peptide. Particular significance is assigned to the comparison of the currently widest used method, ELISA, with various types of LC-MS/MS. The report concludes ELISA being superior to LC-MS/MS methods in terms of recovery and precision, while LC-MS/MS is superior in accuracy, multiplexing, specificity, throughput and sample cost. This suggests that different types of LC-MS/MS has the potential to gain momentum in the field of biomarker quantification if they become more available.
22

Increased system sensitivity using fluorescent based immunoassays on the Gyrolab® platform

Lisra, Gabriel January 2023 (has links)
Immunoassays have become an essential tool in several fields of bioanalytics with tremendous advances in sensitivity and formats seen through the last three decades. Many diseases are today diagnosed solely based on biomarker concentrations evaluated through immunoassays. More biomarkers will be unravelled for diseases that have low serum concentrations once highly sensitive analyzes can be performed routinely, highlighting the importance of improved sensitivity. The aim of this project was to increase the sensitivity of detection on the Gyrolab immunoassay platform. This was done by optimizing the conditions for fluorescence and by reduction of light scattering in the system. Four red-emitting fluorophores were investigated and assays were performed using additives with the purpose to reduce solvent-assisted quenching by water, and to avoid scattering of light in the system’s column. Deuterated solvents and encapsulation strategies were employed to reduce deactivation processes caused by water, and refractive index matching was used to limit the refraction of light. By using heavy water in assay sensitivity was increased by 17-25% for two biomarkers and with the use of different fluorophores showing consistency for the method. With the use of a refractive index matching liquid, it was possible to increase the depth at which the maximum fluorescence intensity occurred three-fold, using confocal microscopy. However, implementing found advantages in assay proved to be difficult due to mediums being hydrophobic and viscous, highlighting the complexity of the microfluidic system.
23

Development and characterization of a colloidal fluorescent ZIF derivative acting as a bio-label for immunoassays

Chapartegui Arias, Ander 19 October 2021 (has links)
In dieser Arbeit ein neues bioanalytisches Konzept untersucht, das nanoskalige Zeolith-Imidazolat-Frameworks (ZIFs) als Marker für antikörperbasierte Analysemethoden einsetzt, einschließlich Enzyme-Linked-Immunosorbent-Assay (ELISA) und Lateral Flow Immunoassay (LFIA). Der Vorteil von ZIFs als Marker gegenüber etablierten Materialien ist ihre vielseitige, einfache und kostengünstige Synthese. Dazu gehört die Möglichkeit, niedermolekulare Substanzen für zusätzliche Sensorzwecke zu verkapseln und für eine hohe Selektivität stabil an Biomakromoleküle zu konjugieren. Als modellhafter Zielanalyt von Relevanz wurden Phthalat-Acylester (PAEs) ausgewählt. Die Relevanz des Nachweises von PAEs ergibt sich aus ihren Eigenschaften als endokrin wirksame Chemikalien (EDCs) und krebserregend. In Kombination mit der Tatsache, dass PAEs aufgrund ihrer Verwendung als Weichmacher in Kindergeschirr, Spielzeug, Trinkflaschen und anderen Produkten auf Polyvinylchlorid-Basis in der Umwelt reichlich vorhanden sind, zeigt, wie wichtig der routinemäßige Nachweis von PAEs in Trinkwasser oder Lebensmitteln ist. / This work explores a new bioanalytical concept that employs nanosized Zeolite Imidazolate Frameworks (ZIFs) particles as labels for antibody-based analytical methods, including enzyme-linked immunosorbent assay (ELISA) and lateral flow immunoassay (LFIA). The advantage of ZIFs as labels over established materials is their versatile, facile, and cheap synthesis. This includes the ability to encapsulate low molecular weight substances for additional sensing purposes and for stable conjugation to biomacromolecules for high selectivity. As a model target analyte of relevance Phthalate acyl esters (PAEs) have been selected. The relevance of the detection of PAEs is due to their properties as endocrine disrupting chemicals (EDCs) and carcinogenic. Combined with PAEs being abundant on the environment because of their use as plasticizers in plastic-made tableware for children, toys, drinking bottles and other polyvinylchloride-based products, shows the importance or their routine detection of drinking water or foods being so critical.
24

Plataformas de baixo custo à base de papel para testes imunodiagnósticos e enzimáticos / Low-cost paper-based platforms for immunodiagnostic and enzymatic testing

Nascimento, Thiago Mazzú do 09 December 2016 (has links)
Os imunoensaios e os ensaios bioquímicos são amplamente utilizados em clinica médica. Os dispositivos fabricados em papel devido ao seu baixo custo, portabilidade, todas as etapas serem realizadas em temperatura ambiente, e possibilidade da produção local dos dispositivos, tornam-se ideais para serem aplicados em regiões carentes. Assim, desenvolvemos um ensaio imunocromatográfico que permitiu a detecção de IgG de coelho em um dispositivo com uma única camada de papel impressa por cera, mostrando que esse protótipo tem potencial de ser aplicado em diferentes ensaios imunológicos. Pela primeira vez foi utilizado um teste enzimático colorimétrico (sarcosina oxidase, peroxidase e o indicador redox (ABTS) em plataforma de papel, impressa por cera, para detecção de sarcosina, o qual detectou um potencial marcador de tumor de câncer de próstata, a sarcosina, com limite de detecção (LD) = 0,21 mmol L-1 e limite de quantificação (LQ) = 0,61 mmol L-1, constatando que a intensidade da cor formada foi proporcional a concentração de sarcosina presente na amostra. Os imunoensaios em papel se mostraram extremamente versáteis, capazes de detectar diferentes analitos. O primeiro dispositivo foi capaz de detectar toxoplasmose (IgG contra T. gondii presente nas amostras). A avaliação da performance do teste nos forneceu um cut-off =21,73 U.A, sensibilidade = 0,96, especificidade = 0,87, AUC = 0,97, além de uma criação de uma zona cinza utilizando uma tolerância em porcentagem sobre a o cut-off de 15%. Desenvolvemos também uma macro no excel qye calcula a acurácia, m-Acuraccy, a qual nos forneceu um valor de 0,88 U.A. O segundo dispositivo permitiu a detecção do marcador tumoral CEA, através de um ensaio do tipo sanduíche, com um cut-off =68,28 U.A, sensibilidade = 0,86, especificidade = 1, AUC = 0,97. A tolerância em porcentagem sobre a o cut-off para a criação da zona cinza foi de 12%, e a m-Acuraccy calculou uma acurácia de 0,90 U.A. Pela primeira vez, foi aplicada essa completa avaliação estatística em testes em papel. Mais do que isso, trazemos com a m-Acuraccy uma nova forma de calcular a acurácia, com grande inovação na clínica médica. Portanto, torna-se evidente o grande potencial que os dispositivos fabricados em papel possuem para ser aplicados como ferramentas diagnósticas. / Immunoassays and bioassays are broadly used in clinical medicine. Paper-based devices are ideal to be used in remote regions due to their low-cost, portability and the possibility of in loco manufacture. Paper-based immunoassays are extremely versatile, capable of detecting distinct analytes: initially we have developed an immunochromatographic assay to detect rabbit IgG in a paper-based device fabricated using wax printing technology, and we have shown that this prototype has potential to be applied in distinct immunoassays. The second developed paper-based device was an enzymatic colorimetric assay for the detection of a potential prostate cancer biomarker - sarcosine (sarcosine oxidase, peroxidase and redox indicator (ABTS)), obtaining good figures or merit (LOD = 0.21 mmol L-1; LOQ = 0.61 mmol L-1, r² = 0.890). The third developed paper-based device was capable of detecting toxoplasmosis (IgG against Toxoplasma gondii in human serum samples). The performance evaluation showed a cut-off = 21.73 A.U., sensitivity = 0.96, specificity = 0.87, AUC = 0.97, besides defining the gray zone as the zone comprehended in-between 15% over the cut-off value. We also have developed a Microsoft Excel® macro to calculate diagnostic test\'s accuracy - m-Accuracy - that is a new way to calculate accuracy with great innovation for clinical medicine, which resulted in an accuracy of 0.88. for toxoplasmosis assay. The fourth developed paper-based device was used to detect CEA tumor biomarker using a sandwich ELISA assay, with a cut-off = 68.28 A.U., sensitivity = 0.86, specificity = 1.0, AUC = 0.97. The defined gray zone to this test was the zone comprehended in-between 12% over the cut-off value, with an accuracy of 0.90. To the best of our knowledge, this is the first complete statistical evaluation of paper-based diagnostic devices, which showed the great potential of this technology to be used as a new point-of care diagnostic tool.
25

Desenvolvimento de ensaios imunoenzimáticos para otimização da detecção de IgG anti - T.gondii em saliva humana / Development of immunoassays for optimizing the detection of IgG anti- T. gondii in human saliva

Sampaio, Barbara Fialho Carvalho 22 November 2012 (has links)
A toxoplasmose afeta cerca de um bilhão de pessoa em todo mundo, é geralmente assintomática, apesar de doença ocular ou doenças grave e letal em fetos, pacientes com HIV e transplantados. A sorologia é a principal ferramenta para o diagnóstico e determinação de incidência, que é uma tarefa difícil, devido à alta prevalência na maioria dos países. Estudos de incidência são ideais em crianças, mas este grupo é protegido pela sociedade e de difícil abordagem por métodos invasivos como a punção venosa. A saliva pode ser uma ótima alternativa por sua coleta não ser invasiva, aceitável para crianças, e conter pequenas quantidades de IgG, eliminada através da mucosa gengival e fluido crevicular. Métodos de detcção de anticorpos disponíveis no mercado estão focados em amostras de soro, com baixa sensibilidade e são raros os relatos de pesquisas com material biológico alternativo, como a saliva. Sendo assim, padronizamos imunoensaios com alta sensibilidade para detecção de anticorpos anti- T. gondii na saliva frente a amostras de soro de 20 voluntários adultos. A sensibilidade e especificidade dos nossos dot-ELISA e ELISA de captura com proteína A foram semelhantes entre soro e saliva. Também testamos 100 amostras de saliva de universitários em nossos ensaios, onde mostramos uma frequência da toxoplasmose de 19% (IC 95% 12-28%). Imunoensaios para detecção de IgG anti-T. gondii em saliva são uma ferramenta muito promissora para estudos epidemiológicos da toxoplasmose em crianças ou outros grupos protegidos. / Toxoplasmosis that affects about one billion people worldwide is usually asymptomatic, despite ocular disease and severe and lethal disease in fetuses, AIDS patients and transplant recipients. Serology is the main approach for diagnosis and incidence determination is a difficult task due to high prevalence in most countries. Incidence studies are feasible in children but this age group is protected and difficult to approach by invasive methods as venipuncture. Saliva could be obtained by non-invasive procedure, acceptable for children, and it contains small amounts of IgG from mucosal and gingival crevicular fluid. Available antibody detection methods are focused in serum samples, with low sensitivity and few reports of alternative biological material, like saliva. Here, we standardized immunoassays with high sensitivity for detection of anti-T. gondii IgG in paired saliva and serum sample from 20 adult volunteers, which allows DOT-ELISA and a Protein A IgG capture assay. The sensitivity and specificity of the saliva DOT-ELISA were similar to sera ELISA. We also tested 100 saliva samples from university graduates in all assays, showing 19% (95%CI 12-28%) frequency of toxoplasmosis in this group, lower than reported for our area. Protein A IgG capture saliva assay was also efficient with similar results. Immunoassay with saliva IgG for toxoplasmosis is a very promising tool for use for the epidemiology of toxoplasmosis in children or other protected groups.
26

Optical Detection Using Computer Screen Photo-assisted Techniques and Ellipsometry

Bakker, Jimmy W. P. January 2006 (has links)
Two main subjects, ellipsometry and computer screen photo-assisted techniques (CSPT), form the main line in this thesis. Ellipsometry is an optical technique based on the detection of polarization changes of light upon interaction with a sample. As most optical detection techniques it is non-intrusive and an additional advantage is its high surface sensitivity: thickness resolution in the order of pm can in principle be achieved. Therefore, ellipsometry is widely used as a technique for determination of optical constants and layer thickness for thin-layer structures. Lately ellipsometry has also been proposed for sensing applications, utilizing the detection of changes in the properties of thin layers. One application is described in this thesis concerning the detection of volatile organic solvents in gas phase using modified porous silicon layers, fabricated by electrochemical etching of silicon to create nm-sized pores. This greatly increases the surface area, promoting gas detection because the number of adsorption sites increases. Other applications of ellipsometry discussed in this thesis are based on combination with CSPT. CSPT is a way to exploit existing optical techniques for use in low-cost applications. In CSPT the computer screen itself is used as a (programmable) light source for optical measurements. For detection a web camera can be used and the whole measurement platform is formed by the computer. Since computers are available almost everywhere, this is a promising way to create optical measurement techniques for widespread use, for example in home-diagnostics. Since the only thing that needs to be added is a sample holder governing the physical or chemical process and directing the light, the cost can be kept very low. First, the use of CSPT for the measurement of fluorescence is described. Fluorescence is used in many detection applications, usually by chemically attaching a fluorescent marker molecule to a suitable species in the process and monitoring the fluorescent emission. The detection of fluorescence is shown to be possible using CSPT, first in a cuvette-based setup, then using a custom designed micro array. In the latter, polarizers were used for contrast enhancement, which in turn led to the implementation of an existing idea to test CSPT for ellipsometry measurements. In a first demonstration, involving thickness measurement of silicon dioxide on silicon, a thickness resolution in the order of nm was already achieved. After improvement of the system, gradients in protein layers could be detected, opening the door toward biosensor applications. Some further development will be needed to make the CSPT applications described here ready for the market, but the results so far are certainly promising.
27

Desenvolvimento de ensaios imunoenzimáticos para otimização da detecção de IgG anti - T.gondii em saliva humana / Development of immunoassays for optimizing the detection of IgG anti- T. gondii in human saliva

Barbara Fialho Carvalho Sampaio 22 November 2012 (has links)
A toxoplasmose afeta cerca de um bilhão de pessoa em todo mundo, é geralmente assintomática, apesar de doença ocular ou doenças grave e letal em fetos, pacientes com HIV e transplantados. A sorologia é a principal ferramenta para o diagnóstico e determinação de incidência, que é uma tarefa difícil, devido à alta prevalência na maioria dos países. Estudos de incidência são ideais em crianças, mas este grupo é protegido pela sociedade e de difícil abordagem por métodos invasivos como a punção venosa. A saliva pode ser uma ótima alternativa por sua coleta não ser invasiva, aceitável para crianças, e conter pequenas quantidades de IgG, eliminada através da mucosa gengival e fluido crevicular. Métodos de detcção de anticorpos disponíveis no mercado estão focados em amostras de soro, com baixa sensibilidade e são raros os relatos de pesquisas com material biológico alternativo, como a saliva. Sendo assim, padronizamos imunoensaios com alta sensibilidade para detecção de anticorpos anti- T. gondii na saliva frente a amostras de soro de 20 voluntários adultos. A sensibilidade e especificidade dos nossos dot-ELISA e ELISA de captura com proteína A foram semelhantes entre soro e saliva. Também testamos 100 amostras de saliva de universitários em nossos ensaios, onde mostramos uma frequência da toxoplasmose de 19% (IC 95% 12-28%). Imunoensaios para detecção de IgG anti-T. gondii em saliva são uma ferramenta muito promissora para estudos epidemiológicos da toxoplasmose em crianças ou outros grupos protegidos. / Toxoplasmosis that affects about one billion people worldwide is usually asymptomatic, despite ocular disease and severe and lethal disease in fetuses, AIDS patients and transplant recipients. Serology is the main approach for diagnosis and incidence determination is a difficult task due to high prevalence in most countries. Incidence studies are feasible in children but this age group is protected and difficult to approach by invasive methods as venipuncture. Saliva could be obtained by non-invasive procedure, acceptable for children, and it contains small amounts of IgG from mucosal and gingival crevicular fluid. Available antibody detection methods are focused in serum samples, with low sensitivity and few reports of alternative biological material, like saliva. Here, we standardized immunoassays with high sensitivity for detection of anti-T. gondii IgG in paired saliva and serum sample from 20 adult volunteers, which allows DOT-ELISA and a Protein A IgG capture assay. The sensitivity and specificity of the saliva DOT-ELISA were similar to sera ELISA. We also tested 100 saliva samples from university graduates in all assays, showing 19% (95%CI 12-28%) frequency of toxoplasmosis in this group, lower than reported for our area. Protein A IgG capture saliva assay was also efficient with similar results. Immunoassay with saliva IgG for toxoplasmosis is a very promising tool for use for the epidemiology of toxoplasmosis in children or other protected groups.
28

Plataformas de baixo custo à base de papel para testes imunodiagnósticos e enzimáticos / Low-cost paper-based platforms for immunodiagnostic and enzymatic testing

Thiago Mazzú do Nascimento 09 December 2016 (has links)
Os imunoensaios e os ensaios bioquímicos são amplamente utilizados em clinica médica. Os dispositivos fabricados em papel devido ao seu baixo custo, portabilidade, todas as etapas serem realizadas em temperatura ambiente, e possibilidade da produção local dos dispositivos, tornam-se ideais para serem aplicados em regiões carentes. Assim, desenvolvemos um ensaio imunocromatográfico que permitiu a detecção de IgG de coelho em um dispositivo com uma única camada de papel impressa por cera, mostrando que esse protótipo tem potencial de ser aplicado em diferentes ensaios imunológicos. Pela primeira vez foi utilizado um teste enzimático colorimétrico (sarcosina oxidase, peroxidase e o indicador redox (ABTS) em plataforma de papel, impressa por cera, para detecção de sarcosina, o qual detectou um potencial marcador de tumor de câncer de próstata, a sarcosina, com limite de detecção (LD) = 0,21 mmol L-1 e limite de quantificação (LQ) = 0,61 mmol L-1, constatando que a intensidade da cor formada foi proporcional a concentração de sarcosina presente na amostra. Os imunoensaios em papel se mostraram extremamente versáteis, capazes de detectar diferentes analitos. O primeiro dispositivo foi capaz de detectar toxoplasmose (IgG contra T. gondii presente nas amostras). A avaliação da performance do teste nos forneceu um cut-off =21,73 U.A, sensibilidade = 0,96, especificidade = 0,87, AUC = 0,97, além de uma criação de uma zona cinza utilizando uma tolerância em porcentagem sobre a o cut-off de 15%. Desenvolvemos também uma macro no excel qye calcula a acurácia, m-Acuraccy, a qual nos forneceu um valor de 0,88 U.A. O segundo dispositivo permitiu a detecção do marcador tumoral CEA, através de um ensaio do tipo sanduíche, com um cut-off =68,28 U.A, sensibilidade = 0,86, especificidade = 1, AUC = 0,97. A tolerância em porcentagem sobre a o cut-off para a criação da zona cinza foi de 12%, e a m-Acuraccy calculou uma acurácia de 0,90 U.A. Pela primeira vez, foi aplicada essa completa avaliação estatística em testes em papel. Mais do que isso, trazemos com a m-Acuraccy uma nova forma de calcular a acurácia, com grande inovação na clínica médica. Portanto, torna-se evidente o grande potencial que os dispositivos fabricados em papel possuem para ser aplicados como ferramentas diagnósticas. / Immunoassays and bioassays are broadly used in clinical medicine. Paper-based devices are ideal to be used in remote regions due to their low-cost, portability and the possibility of in loco manufacture. Paper-based immunoassays are extremely versatile, capable of detecting distinct analytes: initially we have developed an immunochromatographic assay to detect rabbit IgG in a paper-based device fabricated using wax printing technology, and we have shown that this prototype has potential to be applied in distinct immunoassays. The second developed paper-based device was an enzymatic colorimetric assay for the detection of a potential prostate cancer biomarker - sarcosine (sarcosine oxidase, peroxidase and redox indicator (ABTS)), obtaining good figures or merit (LOD = 0.21 mmol L-1; LOQ = 0.61 mmol L-1, r² = 0.890). The third developed paper-based device was capable of detecting toxoplasmosis (IgG against Toxoplasma gondii in human serum samples). The performance evaluation showed a cut-off = 21.73 A.U., sensitivity = 0.96, specificity = 0.87, AUC = 0.97, besides defining the gray zone as the zone comprehended in-between 15% over the cut-off value. We also have developed a Microsoft Excel® macro to calculate diagnostic test\'s accuracy - m-Accuracy - that is a new way to calculate accuracy with great innovation for clinical medicine, which resulted in an accuracy of 0.88. for toxoplasmosis assay. The fourth developed paper-based device was used to detect CEA tumor biomarker using a sandwich ELISA assay, with a cut-off = 68.28 A.U., sensitivity = 0.86, specificity = 1.0, AUC = 0.97. The defined gray zone to this test was the zone comprehended in-between 12% over the cut-off value, with an accuracy of 0.90. To the best of our knowledge, this is the first complete statistical evaluation of paper-based diagnostic devices, which showed the great potential of this technology to be used as a new point-of care diagnostic tool.
29

Produção e caracterização de anticorpos monoclonais contra InlA de Listeria monocytogenes / Production and characterization of monoclonal antibodies against InlA from Listeria monocytogenes

Mendonça, Marcelo 10 March 2008 (has links)
Made available in DSpace on 2014-08-20T14:37:55Z (GMT). No. of bitstreams: 1 dissertacao_marcelo_mendonca.pdf: 563837 bytes, checksum: b7cfe13cc7ba52f1c762a5c48b290205 (MD5) Previous issue date: 2008-03-10 / The food pathogen Listeria monocytogenes is the causative agent of listeriosis, a severe disease that courses with high rates of morbid and mortality. The conventional methods used for detection of this bacterium are laborious and expensive, requiring several days for final identification. Monoclonal antibody (Mab) based immunoassays used for rapid detection of L. monocytogenes have the advantage of being highly specific, particularly if the MAbs are directed against virulence factors conserved among pathogenic strains. Membrane protein internalin A (InlA) from L. monocytogenes is a well characterized virulence factor involved in its adhesion to and internalization in non-phagocytic cells of the host. This work reports on the production and characterization of a panel of MAbs against InlA of L. monocytogenes. For MAbs production, isogenic BALB/c mice were immunized with a recombinant fragment of InlA (rInlA) expressed in Escherichia coli. Five hybridomas secreting MAbs anti-rInlA were generated. The MAbs affinity constants (Ka) were among 7x107 L.mol-1 e 4x106 L.mol-1. The MAbs recognized specifically the species L. monocytogenes by indirect ELISA and Western blot. In indirect ELISA using live or heat-killed L. monocytogenes the MAbs recognized InlA only in bacteria that were grown in Listeria enrichment broth and that were not heated. Western blot analysis revealed that MAbs recognized a band around 88kDa in the L. monocytogenes strains, the molecular mass expected for InlA in its native form. The MAbs produced in this study have potential for use in immunoassays for the detection of L. monocytogenes. / O patógeno alimentar Listeria monocytogenes é o agente causador da listeriose, uma doença severa que cursa com altas taxas de morbidade e de mortalidade. Os métodos convencionais empregados para detecção desta bactéria são laboriosos e onerosos, requerendo vários dias para sua identificação final. Imunoensaios usados para detecção rápida desta bactéria que utilizam anticorpos monoclonais (MAbs) tem como vantagem a alta especificidade, especialmente quando os MAbs são dirigidos contra fatores de virulência conservados nas cepas patogênicas. Entre os diversos fatores de virulência de L. monocytogenes, a proteína de membrana internalina A (InlA), necessária para a aderência e internalização em células não fagocíticas do hospedeiro, é umas das mais bem caracterizadas. Neste trabalho é relatado a produção e caracterização de um painel de MAbs contra a InlA. Na produção dos MAbs, camundongos isogênicos BALB/c foram imunizados com um fragmento recombinante da proteína InlA (rInlA) expresso em Escherichia coli. Foram gerados cinco hibridomas secretores de MAbs anti-rInlA. A constante de afinidade (Ka) dos cinco MAbs situou-se entre 7x107 L.mol-1 e 4x106 L.mol-1. Na caracterização por ELISA indireto e Western blot os MAbs reconheceram especificamente a espécie L. monocytogenes. No ELISA indireto com células de L. monocytogenes vivas ou mortas por tratamento térmico, os MAbs reconheceram somente a InlA nas bactérias que não sofreram tratamento térmico e que foram cultivadas em caldo de enriquecimento para Listeria (LEB). No Western blot os MAbs reconheceram uma banda de aproximadamente 88kDa nas cepas de L. monocytogenes, massa molecular esperada para a proteína InlA em sua forma nativa. Os resultados obtidos nesse trabalho indicam que os MAbs produzidos possuem potencial para serem utilizados em imunoensaios de detecção de L. monocytogenes.
30

Desenvolvimento de ensaio imunoquímico para detecção de doping com eritropoetina / Development of immunochemical assay for detection of doping with erythropoietin

Collares, Thais Farias 17 October 2013 (has links)
Made available in DSpace on 2014-08-20T13:32:48Z (GMT). No. of bitstreams: 1 tese_thais_farias_collares.pdf: 1094762 bytes, checksum: 647dd933472bf9127c0164ee875617ea (MD5) Previous issue date: 2013-10-17 / The history of sports competition has been related to the use of methods for physical training associated with physiological methods to increase athlete performance. Ethical issues involving the high performance sport and doping are confused with the history of competitive sports. The World Anti - Doping Agency (WADA) prohibits the use of substances or methods to artificially increase sports performance. Currently, 258 substances are listed by WADA and athletes around the world are subjected to tests proving the non-use of doping. EPO is a glycoprotein hormone that has as its main physiological effect induction of erythropoiesis and thereby improving the capacity to transport oxygen in the blood. For these reason EPO has been included in WADA list. The analytical differentiation of endogenous erythropoietin from its recombinant counterpart, using isoelectric focusing and double blotting is a milestone in the detection of doping with recombinant erythropoietin. However, several analogs of the original recombinant EPO are not easily detectable by standard IEF method, requiring the development of alternatives for the detection of doping. In order to improve the current methods of EPO detection, monoclonal and polyclonal antibodies against EPO were obtained and used in various techniques for detection of EPO in biological samples. However, the specificity of these antibodies has been quite controversial and discussed. Therefore, it is necessary to obtain antibodies capable of reacting specifically with the EPO. In this study, rHuEPO was inoculated in New Zealand rabbits to generate a polyclonal antibody (pAb anti-rHuEPO). The pAb was characterized for its potential in detecting rHuEPO using different approaches. The pAb anti- rHuEPO identified the expression of recombinant protein in eukaryotic cells and was able to detect rHuEPO in a suspension at 0.1 μg/mL, showing its potential as a tool for detection of doping by rHuEPO. / A história da competição esportiva sempre esteve relacionada à utilização de metodologias de treinamento físico associadas a métodos de incremento fisiológico do atleta, visando sua máxima performance. Questões éticas envolvendo o esporte de alto rendimento e o doping se confundem com a própria história do esporte competitivo. A Agência Mundial Anti-Doping (WADA) proíbe o uso de substâncias ou métodos capazes de aumentar artificialmente o desempenho esportivo. Atualmente, 258 substâncias estão na lista da WADA e atletas do mundo inteiro são submetidos a testes comprobatórios da não utilização do doping. Entre essas substâncias ilícitas para uso por atletas destaca-se a eritropoetina (EPO). A EPO é um hormônio glicoproteico que possui como principal efeito fisiológico a indução da eritropoiese e consequente melhoria da capacidade de transporte de oxigênio no sangue. A diferenciação analítica da eritropoetina endógena produzida a partir de sua contraparte recombinante usando focalização isoelétrica e duplo blotting é um marco na detecção do doping com eritropoetina recombinante. Anticorpos monoclonais e policlonais específicos anti-EPO foram obtidos e utilizados em várias técnicas para a detecção da EPO em amostras biológicas a fim de melhorar os métodos atuais de detecção. Contudo, a especificidade destes anticorpos tem sido bastante controversa e discutida. Portanto, a obtenção de anticorpos específicos capazes de reagir especificamente com a EPO faz-se necessária. Neste estudo, a rHuEPO foi utilizada para imunizar coelhos New Zealand para gerar um anticorpo policlonal (pAb anti-rHuEPO). O pAb foi caracterizado quanto ao seu potencial na detecção da rHuEPO usando diferentes metodologias. O pAb anti-rHuEPO identificou a expressão da proteína recombinante em células eucarióticas e foi capaz de detectar rHuEPO em suspensão até 0,1 μg/mL, comprovando seu potencial como ferramenta para detecção do doping por rHuEPO.

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