Real-time droplet monitoring for digital Polymerase Chain Reaction in microfluidic chip
Autor(a) principal: | |
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Data de Publicação: | 2020 |
Tipo de documento: | Dissertação |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/10362/117487 |
Resumo: | Current cancer diagnosis techniques are often dependent on the collection of tumour tissue, involving invasive processes for the patient. Circulating Tumour DNA (ctDNA) emerges as an alternative resource for cancer detection and monitoring, that can be har vested from simple blood samples. Digital Polymerase Chain Reaction (dPCR) is a fast and sensitive technique for DNA amplification, suitable for low DNA concentrations such as ctDNA. Advances in microfluidics allow the partition of PCR samples into droplets based in water-in-oil emulsions, so that PCR amplification occurs within each droplet. In this way, the PCR reaction is a well controlled process with a low probability of contami nation and allowing a high throughput analysis. The aimed of this work was to develop droplet-based microfluidic device for application to dPCR technique coupled with real-time droplet monitoring. This work focused on the design and fabrication of a microfluidic device capable of producing a large number of uniform droplets with volumes in the nanoliter range and constant frequency. For this, a polydimethylsiloxane (PDMS) droplet generator device was developed, through photo and soft-lithography techniques, and tested with several oil/water flow rates ratios. Then, the droplets generated were characterized in terms of droplet size, velocity and frequency through the implementation of a powerful open-source software for real-time analysis. Several tests on different devices were carried out to evaluate the device reproducibility. Finally, the droplet generator was incorporated with a serpentine design, allowing the PCR cycles to occur in continuous flow. The results revealed that was possible to generate droplets with radius between 22-99 µm and a coefficient of variation bellow 10%. The correspondents volumes ranged between 90 pL-4.18 nL. Moreover, the velocities obtained situated between 0.05 mm/s-7.62 mm/s with droplet generating frequency of 2-50 Hz. Regarding to the droplet monitoring, the results of the workflows developed revealed similarity with the results obtained trough a widely used software for this purposes, with the advantage of allowing real-time analysis for a larger sample of results. |
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Real-time droplet monitoring for digital Polymerase Chain Reaction in microfluidic chipdPCRMicrofluidicDroplet generatorDroplet-based microfluidiclabel-freereal-time droplet monitoringDomínio/Área Científica::Engenharia e Tecnologia::NanotecnologiaCurrent cancer diagnosis techniques are often dependent on the collection of tumour tissue, involving invasive processes for the patient. Circulating Tumour DNA (ctDNA) emerges as an alternative resource for cancer detection and monitoring, that can be har vested from simple blood samples. Digital Polymerase Chain Reaction (dPCR) is a fast and sensitive technique for DNA amplification, suitable for low DNA concentrations such as ctDNA. Advances in microfluidics allow the partition of PCR samples into droplets based in water-in-oil emulsions, so that PCR amplification occurs within each droplet. In this way, the PCR reaction is a well controlled process with a low probability of contami nation and allowing a high throughput analysis. The aimed of this work was to develop droplet-based microfluidic device for application to dPCR technique coupled with real-time droplet monitoring. This work focused on the design and fabrication of a microfluidic device capable of producing a large number of uniform droplets with volumes in the nanoliter range and constant frequency. For this, a polydimethylsiloxane (PDMS) droplet generator device was developed, through photo and soft-lithography techniques, and tested with several oil/water flow rates ratios. Then, the droplets generated were characterized in terms of droplet size, velocity and frequency through the implementation of a powerful open-source software for real-time analysis. Several tests on different devices were carried out to evaluate the device reproducibility. Finally, the droplet generator was incorporated with a serpentine design, allowing the PCR cycles to occur in continuous flow. The results revealed that was possible to generate droplets with radius between 22-99 µm and a coefficient of variation bellow 10%. The correspondents volumes ranged between 90 pL-4.18 nL. Moreover, the velocities obtained situated between 0.05 mm/s-7.62 mm/s with droplet generating frequency of 2-50 Hz. Regarding to the droplet monitoring, the results of the workflows developed revealed similarity with the results obtained trough a widely used software for this purposes, with the advantage of allowing real-time analysis for a larger sample of results.As técnicas actuais usadas no diagnóstico de cancro, geralmente dependem da recolha de tecido tumoral, envolvendo processos invasivos para o paciente. O DNA tumoral circu lante (ctDNA) surge como alternativa para a detecção e monitorização do cancro, podendo ser extraído através de amostras de sangue. A reação em cadeia da polimerase de modo digital (dPCR) é uma técnica rápida e sensível para amplificação de DNA, adequado para baixas concentrações de DNA, como o ctDNA. Os avanços na microfluídica permitem a partição das amostras de PCR em gotas com base em emulsões de água em óleo, de modo que a amplificação por PCR ocorra dentro de cada gota. Deste modo, a reação de PCR é um processo bem controlado com baixa probabilidade de contaminação, permitindo uma análise de alto rendimento. Este trabalho teve como objetivo o desenho e a fabricação de um dispositivo de micro fluídica capaz de produzir um elevado número de gotas uniformes, cujos volumes se encontram na gama dos nanolitros, com frequência constante. Para tal, foi desenvolvido um dispositivo para geração de gotas em polidimetilsiloxano (PDMS), através de técnicas de fotolitografia e litografia suave, tendo sido testado com diversas taxas de fluxos entre óleo / água. Posteriormente, as gotas geradas foram caracterizadas em relação ao seu ta manho, velocidade e frequência através do software de análise de vídeo Bonsai. Diversos testes em diferentes dispositivos foram realizados de modo a avaliar a reprodutibilidade do dispositivo. Por último, o gerador de gotas foi incorporado com desenho da serpentina, permitindo que os ciclos de PCR ocorram em fluxo contínuo. Os estudos realizados revelaram que foi possível gerar gotas com raios entre 22-99 µm, e coeficiente de variação inferior a 10%. Os volumes correspondentes variaram entre 90 pL 4.18 nL. Além disso, as velocidades obtidas situaram-se entre 0.05 mm/s-7.62 mm/s com frequência de geração de gotas de 2-50 Hz. Relativamente à monitorização das gotas, os resultados dos workflows desenvolvidos revelaram similaridade com os resultados obtidos através de um software amplamente utilizado para estes fins, com a vantagem de permitir a análise em tempo real para uma amostra maior de resultados.Neto, JoanaÁguas, HugoRUNMota, Ana Catarina Candeias2021-05-11T09:35:24Z2021-0320202021-03-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisapplication/pdfhttp://hdl.handle.net/10362/117487enginfo:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2024-03-11T05:00:34Zoai:run.unl.pt:10362/117487Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-20T03:43:37.744958Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Real-time droplet monitoring for digital Polymerase Chain Reaction in microfluidic chip |
title |
Real-time droplet monitoring for digital Polymerase Chain Reaction in microfluidic chip |
spellingShingle |
Real-time droplet monitoring for digital Polymerase Chain Reaction in microfluidic chip Mota, Ana Catarina Candeias dPCR Microfluidic Droplet generator Droplet-based microfluidic label-free real-time droplet monitoring Domínio/Área Científica::Engenharia e Tecnologia::Nanotecnologia |
title_short |
Real-time droplet monitoring for digital Polymerase Chain Reaction in microfluidic chip |
title_full |
Real-time droplet monitoring for digital Polymerase Chain Reaction in microfluidic chip |
title_fullStr |
Real-time droplet monitoring for digital Polymerase Chain Reaction in microfluidic chip |
title_full_unstemmed |
Real-time droplet monitoring for digital Polymerase Chain Reaction in microfluidic chip |
title_sort |
Real-time droplet monitoring for digital Polymerase Chain Reaction in microfluidic chip |
author |
Mota, Ana Catarina Candeias |
author_facet |
Mota, Ana Catarina Candeias |
author_role |
author |
dc.contributor.none.fl_str_mv |
Neto, Joana Águas, Hugo RUN |
dc.contributor.author.fl_str_mv |
Mota, Ana Catarina Candeias |
dc.subject.por.fl_str_mv |
dPCR Microfluidic Droplet generator Droplet-based microfluidic label-free real-time droplet monitoring Domínio/Área Científica::Engenharia e Tecnologia::Nanotecnologia |
topic |
dPCR Microfluidic Droplet generator Droplet-based microfluidic label-free real-time droplet monitoring Domínio/Área Científica::Engenharia e Tecnologia::Nanotecnologia |
description |
Current cancer diagnosis techniques are often dependent on the collection of tumour tissue, involving invasive processes for the patient. Circulating Tumour DNA (ctDNA) emerges as an alternative resource for cancer detection and monitoring, that can be har vested from simple blood samples. Digital Polymerase Chain Reaction (dPCR) is a fast and sensitive technique for DNA amplification, suitable for low DNA concentrations such as ctDNA. Advances in microfluidics allow the partition of PCR samples into droplets based in water-in-oil emulsions, so that PCR amplification occurs within each droplet. In this way, the PCR reaction is a well controlled process with a low probability of contami nation and allowing a high throughput analysis. The aimed of this work was to develop droplet-based microfluidic device for application to dPCR technique coupled with real-time droplet monitoring. This work focused on the design and fabrication of a microfluidic device capable of producing a large number of uniform droplets with volumes in the nanoliter range and constant frequency. For this, a polydimethylsiloxane (PDMS) droplet generator device was developed, through photo and soft-lithography techniques, and tested with several oil/water flow rates ratios. Then, the droplets generated were characterized in terms of droplet size, velocity and frequency through the implementation of a powerful open-source software for real-time analysis. Several tests on different devices were carried out to evaluate the device reproducibility. Finally, the droplet generator was incorporated with a serpentine design, allowing the PCR cycles to occur in continuous flow. The results revealed that was possible to generate droplets with radius between 22-99 µm and a coefficient of variation bellow 10%. The correspondents volumes ranged between 90 pL-4.18 nL. Moreover, the velocities obtained situated between 0.05 mm/s-7.62 mm/s with droplet generating frequency of 2-50 Hz. Regarding to the droplet monitoring, the results of the workflows developed revealed similarity with the results obtained trough a widely used software for this purposes, with the advantage of allowing real-time analysis for a larger sample of results. |
publishDate |
2020 |
dc.date.none.fl_str_mv |
2020 2021-05-11T09:35:24Z 2021-03 2021-03-01T00:00:00Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/masterThesis |
format |
masterThesis |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10362/117487 |
url |
http://hdl.handle.net/10362/117487 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
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application/pdf |
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RCAAP |
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RCAAP |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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