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Real-time PCR and it´s use in food processing
Tomanová, Barbora ; Pravečková, Martina (referee) ; Trachtová, Štěpánka (advisor)
Polymerase chain reaction (PCR) is a method abundantly used in molecular diagnostics. PCR in real time or quantitative PCR (qPCR) is one of its modifications and thanks to its advantages it finds still wider utilization nowadays. It finds its use in the food-processing industry too with relatively precise detection, identification, and qualification of both desirable and undesirable components in food, which often brings considerable difficulties and leads to an intensive development of this method. In the experimental part a DNA was isolated from dairy product Bio Via Natur drink for its further processing by means of PCR and gain more detailed information about a bacterial composition using real-time PCR and HRM analysis.
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Application of the method PCR-HRM analysis to identify bacteria in foods and food supplements
Šurková, Alice ; Illková, Kateřina (referee) ; Trachtová, Štěpánka (advisor)
Theoretical part of the thesis was focused on foods and food supplements containing microorganisms, especially bacteria. Furthermore, the thesis deals with methods for identification of the bacteria, primarily polymerase chain reaction (PCR). The thesis also includes real-time PCR and is specially focused on high resolution melting analysis (HRM). During the experimental part, the DNA sample was isolated from a chosen probiotics product using magnetic microparticles. The concentration of the DNA sample was determinate and DNA was subjected to PCR with subsequent detection PCR products by agarose gel electrophoresis. To the results specify HRM analysis was then performed.
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Optimization of DNA isolation form yogurt cultures and their detection by RT-PCR
Šurková, Alice ; Němcová, Andrea (referee) ; Brázda, Václav (advisor)
The thesis has optimized DNA isolation from pure yoghurt cultures and yoghurt products. The isolated DNA was than subjected to RT-PCR analysis. In the first part of the thesis, DNA isolation from pure yoghurt cultures using a commercial kit was evaluated as more effective than isolation by phenol extraction and magnetic microparticles. To assess the quality and quantity of DNA obtained the spectrophotometric determination of concentration and purity and qPCR were used. DNA of a total of ten pure yoghurt cultures in a quality suitable for PCR was obtained using the commercial kit. In the second part of the thesis, bacterial DNA was isolated from yoghurt products using the same commercial kit with a previous sample washing by lysation solution. DNA of six yoghurt products was isolated this way. Furthermore, two packages of homemade yoghurt were mad of each product, of which DNA was isolated in the same way. DNA obtained from yoghurts was subjected to RT-PCR using six pairs of primers (V3_F a V3_R, V6_F a V6_R, V1_F a V1_R, GroHRM_F a GroHRM_R, UPF a UPR, P1V1 a P2V1) and using the pure cultures DNA as a positive controls. The results confirmed the presence of cultures declared in each yoghurt and their ability to multiply after inoculation into a new medium (milk).
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Digital PCR development
Gaňová, Martina ; Lipov,, Jan (referee) ; Jansová,, Eva (referee) ; Neužil, Pavel (advisor)
Mikrotechnologické a nanotechnologické metody se v posledních letech ukázaly jako účinný nástroj pro analýzu deoxyribonukleové kyseliny (DNA). Různé techniky vyvinuté k amplifikaci nukleových kyselin (NK) byli publikovány v posledním desetiletí, včetně mikrofluidních systémů. Polymerázová řetězová reakce (PCR) je v molekulární biologii široce používána k amplifikaci cílové NK in vitro. Počet skupin pracujících s PCR po celém světě je obrovský vzhledem k důležitému sociálnímu a ekonomickému dopadu této techniky, například v oblasti lékařské diagnostiky, kriminalistiky, zpracování potravin nebo environmentálních studií. V současné době pandemie koronavirového onemocnění 2019 se prokázala důležitost vývoje přístupnějších technologií pro diagnostiku virových onemocnění. Disertační práce popisuje vývoj dvou verzí platforem PCR pro detekci NK, kapkovou kvantitativní PCR v reálném čase (qPCR) a digitální PCR (dPCR). Klíčové komponenty obou platforem byly vyrobeny pomocí mikrotechnologických postupů pro úpravu povrchů a litografickou výrobu umožňující vývoj hydrofobních krycích skel nebo křemíkových mikročipů. Výsledky práce demonstrují návrh, sestavení a testování včetně optimalizace obou platforem. Technologie PCR je tvořena softwarovou částí, ovládanou programem LabView a hardwarovou častí sestávající ze systému řízení teploty a zobrazovacího systém florescence. Kapková qPCR byla prováděna v 0.3 µL kapky směsi obsahující cílový gen napipetovaný v objemu 2 µL kapky minerálního oleje. Kapky byly pipetovány na hydrofobní krycí sklo, které bylo umístěno na termoelektrický chladič (TEC) pod fluorescenční mikroskop, aby se provedlo teplotní cyklování. Změny fluorescence během cyklů byly zachyceny fotonásobičem a sledovány osciloskopem. Výsledky testování popisují také schopnost multiplexování vyvinuté techniky. V práci je představená amplifikace tří syntetických genů s využitím interkalačního fluorescenčního barviva pro simultánní detekci a kvantifikaci na základě jednoho fluorescenčního kanálu. Kapková technologie qPCR byla zásadní platformou pro další vývoj platformy dPCR. Platforma dPCR používá křemíkový mikročip s disperzí vzorku do mikrojamek o celkovém počtu 26 448, každá s průměrem 50 µm a objemem 59 pL. Mikročip naplněn vzorkem byl pokryt minerálním olejem a krycím sklem modifikovaným polydimethylsiloxanem a Parylenem C. Systém ohřevu/chlazení teplotního cyklování s TEC byl podobný jako u kapkové platformy qPCR. Fluorescenční zobrazovací systém používal k zachycení fluorescenčních obrazů polovodičovou kameru na bázi CMOS. Vyvinutá dPCR byla testována pro aplikace ve výzkumu humánní medicíny. Testovací vzorky DNA byly část syntetického genu viru, izolovaná genomická DNA viru a izolovaná genomická DNA ženy. Disertační práce popisuje vývoj systému dPCR, který je součástí nové techniky dPCR, která je cenově dostupnější a snadno použitelná s jednoduchým dávkováním vzorků, což jsou nejčastější problémy, proč si zatím mezi laboratořemi nenašla velkou popularitu. dPCR mikročip na bázi křemíku zlepšil výkon systému díky velkému počtu mikrojamek. Využití technologie dPCR vyniká ve vysoké citlivosti, v nízkém poměru signálu k šumu, dosahované přesnosti, v nízkém detekčním limitu a schopnosti multiplexování.
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The utilization of the uracil-DNA glycosylase in the elimination of carry-over contamination by products of the previous DNA amplifications
Zrnová, Adéla ; Martínková, Markéta (advisor) ; Prošková, Veronika (referee)
DNA amplification is an important tool in diagnosis of infectious diseases. The most commonly used method in laboratories is the polymerase chain reaction, which, does not meet the need for a fast and inexpensive method. It was therefore necessary to develop a method that would be sensitive, fast, specific and accessible, for example, in developing countries with limited access to instrumentation. It appears that LAMP could be this method. Unfortunately, the LAMP method encounters considerable false positivity, which must be prevented in order to be used in practice. The subject of the presented bachelor thesis is the introduction of a unique LAMP method to detect the presence of DNA Streptococcus pneumoniae and the study of the use of uracil- DNA glycosylase to prevent contamination of samples with DNA formed in previous amplification reactions. The LAMP method of DNA detection Streptococcus pneumoniae was successfully introduced, then the method was optimized even in the presence of deoxyuridine triphosphate. After determining the appropriate deoxyuridine triphosphate concentration for LAMP amplification, the resulting Streptococcus pneumoniae DNA amplification products were treated with uracil-DNA glycosylase. This procedure was shown to have the potential to prevent false positivity of other...
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Optimization of DNA isolation form yogurt cultures and their detection by RT-PCR
Šurková, Alice ; Němcová, Andrea (referee) ; Brázda, Václav (advisor)
The thesis has optimized DNA isolation from pure yoghurt cultures and yoghurt products. The isolated DNA was than subjected to RT-PCR analysis. In the first part of the thesis, DNA isolation from pure yoghurt cultures using a commercial kit was evaluated as more effective than isolation by phenol extraction and magnetic microparticles. To assess the quality and quantity of DNA obtained the spectrophotometric determination of concentration and purity and qPCR were used. DNA of a total of ten pure yoghurt cultures in a quality suitable for PCR was obtained using the commercial kit. In the second part of the thesis, bacterial DNA was isolated from yoghurt products using the same commercial kit with a previous sample washing by lysation solution. DNA of six yoghurt products was isolated this way. Furthermore, two packages of homemade yoghurt were mad of each product, of which DNA was isolated in the same way. DNA obtained from yoghurts was subjected to RT-PCR using six pairs of primers (V3_F a V3_R, V6_F a V6_R, V1_F a V1_R, GroHRM_F a GroHRM_R, UPF a UPR, P1V1 a P2V1) and using the pure cultures DNA as a positive controls. The results confirmed the presence of cultures declared in each yoghurt and their ability to multiply after inoculation into a new medium (milk).
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Use of PCR in forensic genetic analysis.
Dvořáková, Lenka ; Šimková, Halina (advisor) ; Vaněk, Daniel (referee)
Polymerase Chain Reaction or PCR is molecular genetic method used to amplify the DNA fragment. Today it is one of the most popular and successful molecular genetic methods, which is used in many scientific and applied fields. PCR has many modifications derived from the classical scheme of reactions - for example multiplex PCR, inverse PCR, nested PCR, asymmetric PCR, and a lot more. The forensic genetic analysis is mainly used as a PCR amplification method of the studied loci for fragment analysis, as part of the sequencing and then quantified as a real-time PCR. The aim of this paper is to summarize the use of polymerase chain reaction in the forensic practice, and outline the methods in which PCR is used.
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Application of the method PCR-HRM analysis to identify bacteria in foods and food supplements
Šurková, Alice ; Illková, Kateřina (referee) ; Trachtová, Štěpánka (advisor)
Theoretical part of the thesis was focused on foods and food supplements containing microorganisms, especially bacteria. Furthermore, the thesis deals with methods for identification of the bacteria, primarily polymerase chain reaction (PCR). The thesis also includes real-time PCR and is specially focused on high resolution melting analysis (HRM). During the experimental part, the DNA sample was isolated from a chosen probiotics product using magnetic microparticles. The concentration of the DNA sample was determinate and DNA was subjected to PCR with subsequent detection PCR products by agarose gel electrophoresis. To the results specify HRM analysis was then performed.
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Real-time PCR and it´s use in food processing
Tomanová, Barbora ; Pravečková, Martina (referee) ; Trachtová, Štěpánka (advisor)
Polymerase chain reaction (PCR) is a method abundantly used in molecular diagnostics. PCR in real time or quantitative PCR (qPCR) is one of its modifications and thanks to its advantages it finds still wider utilization nowadays. It finds its use in the food-processing industry too with relatively precise detection, identification, and qualification of both desirable and undesirable components in food, which often brings considerable difficulties and leads to an intensive development of this method. In the experimental part a DNA was isolated from dairy product Bio Via Natur drink for its further processing by means of PCR and gain more detailed information about a bacterial composition using real-time PCR and HRM analysis.
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Optimization of parameters of the polymerase chain reaction.
VOJTOVÁ, Magda
Abstract The polymerase chain reaction (PCR), is a molecular biological method, which is capable to amplify a particular DNA sequence. Above all, there are recently appeared modifications working on the principle of PCR, which became indispensable not only for the diagnosis of some viral, bacterial and tumoral, but also for the diagnosis of genetically conditioned diseases. The duty of my bachelor thesis is to understand the whole system of this technology, to describe its individual parts, process and principle. The main task of my work was to optimize PCR, in order to achieve its highest specifity, accuracy and yields of PCR products, which would be sufficient for next research and analysis. All optimization steps of amplification were done using cDNA (Spinacia oleracea) of proteins PsbR and PsbQ from photosystem II of higher plants. Instead of PsbR, which amplification was optimized with physical impacts, PsbQ protein was optimized using chemical factors. In the case of these chemical factors used to improve PCR product yields that were different concentrations of individual elemental components as: DNA template, Taq DNA polymerase, dNTPs, primers and magnesium ions. For physical impacts the increase of amplification yields was concentrated primarily on optimization of number of cycles, the right temperature of annealing and the time of extesion In the practical part of this bachelor thesis I present the whole set of resulting gels, with the clear conclusion, which conditions for amplification of PCR products were the most suitable, and which on the contrary were problematical. The well adjusted method was analyzed using the electrophoretic division. Namely it was observation of sharpness of corresponding band and the formation of negative or falsely positive results. For the minimisation of undesirable products were experimentally determined for amplification of PsbQ gene as the most appropriate the following parameters: the lowest concentration of DNA (0.001 ?g/?l), for Taq DNA polymerase the resulting activity 0.05 U/?l. The higher values of both components bring during the amplification formation of secondary products, which restrict the yields of reaction. The finding of the right concentration of dNTPs confirms the need of optimization for amplification of each gene. As the most suitable concentration was choosen 0.2 mM, only twice higher levels of this concentration inhibit the reaction. The concentrations of used primers were corresponding to direct proportion, it means that the higher the levels 0,1-2 ?M were used, the higher the yields of PCR products were obtained in observed 446 bp band. Some publications focused on the evaluation of the right concentration of magnesium ions warn us about the fact that the levels lower than 1.5 mM inhibit the reaction. All higher levels guarantee high-quality yields of amplification. The same conclusion was reached in the case of amplification of the PsbQ gene. Also the principles of optimization of amplification of PsbR gene were based on findings obtained from scientific literature focused on this problematic. The ideal temperature of annealing was 63 °C, indisputed intensification of amplification was accomplished owing to the increase of number of cycles. At least 30 cycles of PCR reaction were sufficient enough to ensure the formation of enough intense 290 bp band. The high-quality amplification was also ensured by 2 minutes long extension, shorter time resulted in none or low yield. All optimized parameters were used for analysis of several unknown samples, where the presence of above mentioned genes ? PsbR, PsbQ had to be ascertained and thus confirmed the optimization of PCR method for investigated genes. The results of optimization will be used in the laboratory like starting protocol.
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