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Fetal DNA circulating in maternal plasma and possibilities of its genetic analysis
Soukalová, Adéla ; Korabečná, Marie (advisor) ; Vodička, Radek (referee)
Cell free DNA is short, fragmented DNA found in plasma and serum, into which it is released by various mechanisms. It was first identified in body fluids of cancer patients and soon became a biomarker for non-invasive diagnostics. Soon after, the presence of fetal cfDNA in maternal plasma was detected and became the subject of clinical utility. Non-invasive prenatal diagnosis is a screening method that helps to determine the likelihood of birth defects early in pregnancy, specifically using fetal cfDNA. The final results are determined by invasive methods such as aminocentesis and chorionic villus sampling. Invasive methods of prenatal diagnosis carry a risk of fetal loss of less than 1 %. Despite this low risk, scientists are constantly striving to improve non-invasive methods that can detect aneuploidies such as Down's or Edwards syndrome, as well as determine the sex of the fetus, monogenic diseases and the Rh factor. Polymerase chain reaction (PCR) or next-generation sequencing methods are used for detection.
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Optimization of calcium chloride concentration for removal of polysaccharide contamination during plant DNA isolation
Frnčová, Ekaterina ; Šlosárová, Katarína (referee) ; Fialová, Lenka (advisor)
The greatest difficulty in isolating DNA is the presence of contaminants that cause side effects. Polysaccharides are the most common contaminants in fruits. They can distort the results in spectrophotometric determination of purity or act as inhibitors in PCR analysis together with other substances (for example, proteins or phenolic substances). The aim of this work was to investigate the influence of different concentrations of calcium chloride on the process of DNA isolation. In the experimental part, DNA from the apple was isolated using different concentrations of calcium chloride. The isolation was carried out four times, and each time the sample was adjusted in different ways. It was found that the isolation method used works only with a sample that has been lyophilized. Isolation of DNA from fresh fruit provided very low yields. Probably, this was due to the large water content in the sample, and the proportion of the solid component was smaller. Subsequently, PCR analysis and electrophoresis were performed to determine the amplifiability of the isolated DNA. Two sets of primers with different specificity were used for this analysis. Amplifiability was confirmed only when using primers specific to apple DNA when using 100 mM solution of CaCl2. Other samples have been amplifiable using both types of primers. Probably, samples isolated using a 100 mM solution of CaCl2 had a larger amount of inhibitors that do not affect all PCR reactions equally, which may also indicate a small effectiveness of this amount of CaCl2.
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Testing and optimization of protocols for removal of contaminants during DNA isolation from hibiscus blossoms
Brabcová, Martina ; Kubalová, Michaela (referee) ; Fialová, Lenka (advisor)
The Roselle (Hibiscus sabdariffa) is a widely used plant in food industry, especially in tea production. The hibiscus flower is rich in polyphenolic substances, which are a major problem in DNA isolation. This work deals with the modification of the CTAB isolation protocol to ensure concentration and purity of DNA sufficient for its amplification. DNA isolated according to the CTAB protocol did not have sufficient concentration and purity for amplification due to high contamination with polyphenolic substances. A procedure with double incubation of plant tissue in CTAB buffer containing 3% polyvinylpyrrolidone (PVP) was proposed to remove it. These isolates were successfully amplified. The effect of PVP concentration (1-5%) in CTAB buffer on the concentration and purity of isolated DNA was also investigated. PCR results showed that double incubation with CTAB buffer had a greater effect on the removal of polyphenolic compounds than changing the PVP concentration. Subsequently, the modified isolation protocol was also successfully used to isolate amplifiable DNA from commercial tea blends.
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DNA extraction from plant tissues for polymerase chain reaction analysis
Trojánek, Zdeněk ; RNDr.Roman Matyášek, CSc. (referee) ; Rittich, Bohuslav (advisor)
Extraction of nucleic acids is an important step for all molecular biological studies. The process of isolation of plant DNA is complicated due to the presence of polyphenols, polysaccharides and other metabolites. They can be co-isolated with DNA and act as PCR inhibitors. The aim of this study was to compare CTAB extraction procedure, Qiagen DNA easy kit, direct homogenization, carboxyl-functionalised magnetic non-porous HEMA based microspheres and combination of the above mentioned methods for DNA isolation from different plants. The DNA was evaluated regarding concentration, purity and amplification in PCR. All methods provided DNA that could be used in downstream PCR applications. However, there were differences regarding yield, purity, labour intensiveness and cost. Combination of direct homogenization and magnetic microspheres coated by carboxyl groups was isolated DNA from various plants and plant foods in a quality suitable for convectional PCR, real time PCR and restriction analysis. This method is fast, simple and does not require work with harmful substances.
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Microbial lipases and their application
Pavlačková, Jana ; Flodrová, Dana (referee) ; Omelková, Jiřina (advisor)
This diploma thesis is focused on the study of the preparation for fat separators and wastewater pipes that contains the microorganisms with lipolytic activity. Theoretical part of this thesis describes lipases, microorganisms producing this enzymes and usage of lipases. In this part possibilities of identification of microorganisms are presented too. The practical part is concerned with the study of commercial preparation Sany Duo Spezial with proven presence of microorganisms with lipolytic activity. These microorganisms were identified by means of the PCR method. This method identified mictoorganisms like genus Bacillus sp. Next characterization of the preparation was focused on the determination of COD and the investigation of the influence of various conditions of culture medium on the lipases production and their activity. The effect of temperature, ions and pH was studied. Lipolytic activity was determine spectrophotometricaly with usage of p-nitrophenyllaurate whitch dissociates to yellow product p-nitrophenol.
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Identification of lactic acid bacteria in fermented dairy products using amplification methods
Tycová, Martina ; Rittich, Bohuslav (referee) ; Španová, Alena (advisor)
Polymerase chain reaction (PCR) is molecular diagnostic method which allows the identification of lactic acid bacteria used in food industry. In this work species-specific PCR primers (targeted on highly conserved 16S rDNA region) were used for identification of bacteria of species Streptoccocus thermophilus in 10 randomly commercially accessible fermented milk products and for identification of species Streptococcus thermophilus in 25 lyophilisates collected in Culture Collection of Dairy Microorganisms Laktoflora (CCDM, Tábor, Czech Republic). The PCR products (968 bp) were detected using electrophoresis in 1,2 % agarose gel. Bacterial DNA was isolated from crude cell lysates by magnetic carriers P(HEMA co GMA) containing carboxyl groups. DNA was reversibly bind on their surface in the presence of high concentrations of poly(ethylene glycol) (PEG 6000) and sodium chloride. Phenol extraction of DNA was used as control. Streptococcus thermophilus strains were identificated using PCR in all analysed samples.
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Lactobacillus DNA analysis using real-time PCR and HRM analysis
Aksamitová, Dagmar ; Illková, Kateřina (referee) ; Trachtová, Štěpánka (advisor)
The rapid and accurate identification of the bacterium of the genus Lactobacillus, which are an important part of the normal gastrointestinal microflora and fermented dairy products are currently mainly used amplification methods. The aim of the study was to analyze the possibility of resolution of selected bacterial strains of the genus Lactobacillus, using the metod of polymerase chain reaction in the real time combined with high resolution melting curve analysis (qPCR HRM). It was tested five primers designed for qPCR-HRM analysis of lactic acid bacteria. The specificity of the primers was also verified simultaneously using bioinformatic analysis. On the basis of analysis of the DNA were selected as the most appropriate primers P1V1/P2V1, V3F/V3R and V6F/V6R. The suitability of the primers V3F/V3R and V6F/V6R was verified on a complex sample of food supplement from which the DNA was isolated using magnetic particles. The presence of bacteria of the genus Lactobacillus was performed using high resoluting melting analysis curves. The obtained results were in agreement with the information given by the manufacturer.
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Microbiological analytical methods suitable for dairy industry
Vlasák, Jaroslav ; Illková, Kateřina (referee) ; Trachtová, Štěpánka (advisor)
The theoretical part of the thesis is focused on probiotics in dairy products. Thesis deals with molecular genetic methods, which are used to analyze DNA. Especially are discussed methods used for isolation bacterial cells belonging to genus Lactobacillus. The polymerase chain reaction (PCR) is the basic technique at present time. Short chain of oligonucleotide primers are used to amplification specific parts of DNA molecule chain. The practical part of the thesis is focused on the DNA from pure bacterial culture and probiotic dairy product. DNA was isolated using methods of phenol-chloroform extraction and magnetic separation. For magnetic separation was used magnetics particles covered with carbonyl functional groups. Quality of the DNA was confirmed by PCR amplification. Primers specific for domain Bacteria and genus Lactobacillus and Bifidobacterium was used.
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Analysis of the composition of selected probiotic products by PCR-HRM
Tomanová, Barbora ; Španová, Alena (referee) ; Trachtová, Štěpánka (advisor)
This work was focused on the detection of probiotic bacteria in four different probiotic products (probiotic cream, probiotic tampons, oral probiotics and soy beverages with probiotics). The viability of the bacteria contained in the products was verified. Complex matrices of the products were used to isolate DNA in a quality suitable for the PCR method, followed by identification of the declared bacterial genus and species. Amplification was achieved with conventional PCR and real-time PCR, genus- and species-specific primers were used. Bacteria, of the genus Lactobacillus and Bacillus and bacterial species Lactobacillus pentosus, Lactobacillus rhamnosus, Lactobacillus fermentum and Lactobacillus gasseri, were proven to be within the products. Subsequently, the DNA from mixed bacterial species in the probiotic tampon were distinguished using PCR-HRM. Five sets of primers were used to test this. Two sets of primers (primers P1V1, P2V1 and V1F-HRM, V1R-HRM) were evaluated as the most suitable for resolution.
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Isolation of PCR-ready DNA from probiotic products for baby nutrition
Mantlová, Gabriela ; Havlíková, Šárka (referee) ; Španová, Alena (advisor)
The aim of thesis is focused on isolation of DNA in quality for polymerase chain reaction (PCR) and the identification of probiotic bacteria. From six probiotic supplements for children were isolated PCR-ready DNAs using magnetic carriers P(HEMA-co-GMA). Isolated DNA was amplified by genus-specific and species-specific primers. DNAs of Lactobacillus, Bifidobacterium and Streptococcus genera were identified as: L. acidophilus, L. rhamnosus, L. casei, B. bifidum, B. longum ssp. longum, B. breve, B. longum ssp infantis, B. animalis and S. thermophilus. The identification corresponded with the data declared by the producers.
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