Extraction Of High-quality DNA Research Articles

Retrieving high-quality genomic DNA from formalin-fixed paraffin-embedded tissues for multiple molecular analyses

Formalin-fixed paraffin-embedded (FFPE) tissues represent the biggest source of archival materials for molecular biology research and pathology investigations. Nevertheless, fixation by formalin may cause denaturation and modification of macromolecules constraining DNA quality and its downstream applications. In this study, we developed a fast, simple, and cost-effective phenol/chloroform-based protocol for the extraction of high-quality DNA from 101 FFPE colorectal cancer tissue blocks that can be used in multiple molecular studies. DNA samples extracted using this phenol/chloroform protocol and the QIAamp DNA FFPE Tissue kit were evaluated for the quantity, quality, and amplificability. Spectrophotometer analyses revealed significantly higher quality and quantity of DNA samples obtained with the phenol/chloroform protocol as compared to those of the QIAamp DNA FFPE Tissue kit. In addition, the amplificability of these samples as assessed by conventional and multiplex polymerase chain reaction (PCR), followed by sequencing and fragment analyses presented an absolute success rate. Additionally, it is able to amplify a DNA fragment of 725 base-pairs at an adequate amount for downstream applications. This fast, simple, and cost-effective method may facilitate the molecular analyses of a large number of FFPE specimens that best suits the needs of the overall study design in terms of the quality and quantity of the extracted DNA.

A Magnetic-Bead-Based Mosquito DNA Extraction Protocol for Next-Generation Sequencing.

A recently published DNA extraction protocol using magnetic beads and an automated DNA extraction instrument suggested that it is possible to extract high quality and quantity DNA from a well-preserved individual mosquito sufficient for downstream whole genome sequencing. However, reliance on an expensive automated DNA extraction instrument can be prohibitive for many laboratories. Here, the study provides a budget-friendly magnetic-bead-based DNA extraction protocol, which is suitable for low to medium throughput. The protocol described here was successfully tested using individual Aedes aegypti mosquito samples. The reduced costs associated with high quality DNA extraction will increase the application of high throughput sequencing to resource limited labs and studies.

TBMT-02. APOLLO: RAMAN-BASED PATHOLOGY OF MALIGNANT GLIOMA

BACKGROUNDDNA methylation is an essential component for integrative diagnosis of gliomas. Methylation subtype prediction of gliomas is currently done via sample extraction of high-quality DNA (~1ug), methylome profiling, followed by probe identification, curation and subsequent analysis via different random forest classifiers. However, the DNA methylation classification is not always available for all the samples. Examples include when the existing material is not suitable for methylation profiling or the sample is very limiting. Therefore, we hypothesized that Raman spectroscopy might be suitable to predict the glioma methylome, based upon its ability to create a molecular fingerprint of the tumor and would provide biological insights unknown before.METHODSCoherent Raman Spectroscopy was used for molecular fingerprinting of the regions of interest using 1mm2 FFPE tissue spots from 39 patient samples with LGm1 to LGm6 methylation subtypes. Spectral information was then used to train a convolutional neural network (CNN) and develop a prediction algorithm, capable of detecting the glioma methylation subtypes. 70 % of the dataset was used for model training while the remaining 30% for validation. Oversampling was used to obtain a subtype-balanced data distribution. In addition, supervised wrapper methods and random forests were used to identify the top 50 most discriminatory Raman frequencies out of 1738.RESULTSWe demonstrate that Raman spectroscopy can accurately and rapidly classify gliomas according to their methylation subtype from achieved FFPE samples, which are routinely present in pathological laboratories as a complementary mean to obtain this important classification when other analyses are not available. The most discriminatory frequencies show differential spectral intensities depending upon the glioma subtypes across the larger areas of the tissue.CONCLUSIONSThe non-destructive nature of this method and the ability to be applied on FFPE samples directly, allows the histopathologist to reuse of the same slide for subsequent staining and downstream analyses.

Optimized High Quality DNA Extraction from Formalin-Fixed Paraffin-Embedded Human Atherosclerotic Lesions

Formalin-fixed paraffin-embedded (FFPE) tissues represent a valuable source for molecular analyses and clinical genomic studies. These tissues are often poor in cells or difficult to process. Therefore, nucleic acids need to be carefully isolated. In recent years, various methods for DNA isolation have been established for tissues from many diseases, mostly cancer. Unfortunately, genomic DNA extracted from FFPE tissues is highly degraded due to the cross-linking between nucleic acid strands and proteins, as well as random breakings in sequence. Therefore, DNA quality from these samples is markedly reduced, making it a challenge for further molecular downstream analyses. Other problems with difficult tissues are, for example, the lack of cells in calcified human atherosclerotic lesions and fatty tissue, small skin biopsies, and consequently low availability of the desired nucleic acids as it is also the case in old or fixed tissues. In our laboratories, we have established a method for DNA extraction from formalin-fixed atherosclerotic lesions, using a semi-automated isolation system. We compared this method to other commercially available extraction protocols and focused on further downstream analyses. Purity and concentration of the DNA were measured by spectrometry and fluorometry. The degree of fragmentation and overall quality were assessed. The highest DNA quantity and quality was obtained with the modified blood DNA protocol for the automated extraction system, instead of the commercial FFPE protocol. With this step-by-step protocol, DNA yields from FFPE samples were in average four times higher and fewer specimens failed the extraction process, which is critical when dealing with small-vessel biopsies. Amplicon sizes from 200-800 bp could be detected by PCR. This study shows that although DNA obtained from our FFPE tissue is highly fragmented, it can still be used for successful amplification and sequencing of shorter products. In conclusion, in our hands, the automated technology appears to be the best system for DNA extraction, especially for small FFPE tissue specimen.

Comparative Evaluation of Different DNA Extraction Methods from E. Longifolia Herbal Medicinal Product

The aphrodisiac property of Eurycoma longifolia has led to an increase in the demand for its Herbal Medicinal Products (HMPs). However, the efficiency of such HMPs depends on the usage of their genuine raw materials. The conventional methods cannot identify species in processed form. The authentication of HMPs can be achieved effectively using DNA barcoding as the method species-specific. However, the use of this method solely relied on the extraction of high-quality DNA from the HMPs. Therefore, it is necessary to establish a satisfactory method for extracting high-quality DNA from the HMPs. Here, four DNA extraction methods were compared to evaluate the best protocol in yield, purity, polymerase chain reaction (PCR) amplification, sequencing, and species identification. The spectrophotometer analysis showed that the Nucleospin Plant II extraction kit has the best purity as this can be severely affected by the presence of various contaminants in the HMPs. Our findings reveal that DNA purity was more important as a predictor for PCR amplification than yield. Therefore, the present study results demonstrate that the Nucleospin Plant II extraction kit is the best because it produces the purest, amplifiable, and sequenceable DNA for identification and authentication of E. Longifolia HMPs.

Herbarium Specimens: A Treasure for DNA Extraction, an Update.

With the expansion of molecular techniques, the historical collections have become widely used. The last boom started with using next- and second-generation sequencing in which massive parallel sequencing replaced targeted sequencing and third-generation technology involves single molecule technology. Studying plant DNA using these modern molecular techniques plays an important role in understanding evolutionary relationships, identification through DNA barcoding, conservation status, and many other aspects of plant biology. Enormous herbarium collections are an important source of material especially for taxonomic long-standing issues, specimens from areas difficult to access or from taxa that are now extinct. The ability to utilize these specimens greatly enhances the research. However, the process of extracting DNA from herbarium specimens is often fraught with difficulty related to such variables as plant chemistry, drying method of the specimen, and chemical treatment of the specimen. The result of these applications is often fragmented DNA. The reason new sequencing approaches have been so successful is that the template DNA needs to be fragmented for proper library building, and herbarium DNA is exactly that. Although many methods have been developed for extraction of DNA from herbarium specimens, the most frequently used are modified CTAB and DNeasy Plant Mini Kit protocols. Nine selected protocols in this chapter have been successfully used for high-quality DNA extraction from different kinds of plant herbarium tissues. These methods differ primarily with respect to their requirements for input material (from algae to vascular plants), type of the plant tissue (leaves with incrustations, sclerenchyma strands, mucilaginous tissues, needles, seeds), and further possible applications (PCR-based methods, microsatellites, AFLP or next-generation sequencing).

Twelve quick steps for genome assembly and annotation in the classroom.

Eukaryotic genome sequencing and de novo assembly, once the exclusive domain of well-funded international consortia, have become increasingly affordable, thus fitting the budgets of individual research groups. Third-generation long-read DNA sequencing technologies are increasingly used, providing extensive genomic toolkits that were once reserved for a few select model organisms. Generating high-quality genome assemblies and annotations for many aquatic species still presents significant challenges due to their large genome sizes, complexity, and high chromosome numbers. Indeed, selecting the most appropriate sequencing and software platforms and annotation pipelines for a new genome project can be daunting because tools often only work in limited contexts. In genomics, generating a high-quality genome assembly/annotation has become an indispensable tool for better understanding the biology of any species. Herein, we state 12 steps to help researchers get started in genome projects by presenting guidelines that are broadly applicable (to any species), sustainable over time, and cover all aspects of genome assembly and annotation projects from start to finish. We review some commonly used approaches, including practical methods to extract high-quality DNA and choices for the best sequencing platforms and library preparations. In addition, we discuss the range of potential bioinformatics pipelines, including structural and functional annotations (e.g., transposable elements and repetitive sequences). This paper also includes information on how to build a wide community for a genome project, the importance of data management, and how to make the data and results Findable, Accessible, Interoperable, and Reusable (FAIR) by submitting them to a public repository and sharing them with the research community.

Development of an Efficient Method to Extract DNA from Refined Soybean Oil

Recently, soybean oil has become the most consumed genetically modified (GM) vegetable oil globally. To monitor products derived from GM sources, DNA-based analysis methods are being widely adopted, particularly to control the authenticity of several food products including oil. Considering that DNA isolation from foodstuffs is the first step in the detection of GM organisms, we compared five different methods to extract high quality DNA from refined soybean oil. We used ultraviolet spectrophotometry, nested polymerase chain reaction (PCR), and real-time PCR to evaluate DNA yield and purity, and the sensitivity of the optimized method was evaluated. According to our results, the most effective DNA extraction method was the cetyltrimethylammonium bromide–NucleoSpin Food Kit method. Using this method, 21–225 DNA copies were isolated from 1 mL soybean or blended oils, and the minimum ratio of soybean oil that could be detected from a mixture of soybean and peanut oil was 5%. To summarize, we report a novel method that combines pre-concentrating oils and commercial kits. This optimized DNA extraction method advances the traceability of soybean oils for authenticity issues and transgenic detection.

Development of an SSR-based DNA fingerprinting method for black wattle (Acacia mearnsii De Wild)

Background: The most commonly used method for extracting DNA from plant leaf tissue involves cetyl trimethylammonium bromide but some species, such as Acacia mearnsii, contain high levels of secondary metabolites and polysaccharides that interfere with this process. Various modifications have been proposed for effective removal of these biomolecules but these methods can be time consuming. Therefore, this study was initiated to optimise the cetyl-trimethylammonium bromide protocol for the extraction of high-quality genomic DNA and to develop a fingerprinting tool using cross species transferable simple sequence repeat markers for genetic diversity studies in A. mearnsii.
 Methods: Five CTAB-based modification were examined and 49 cross-species microsatellite markers, developed for several Acacia species, were tested in four multiplex panels of A. mearnsii populations.
 Results: The modified protocol yields high quantity and quality DNA from A. mearnsii leaves using high concentration of NaCl to remove polysaccharides and polyvinylpolypyrrolidone (PVPP) to eliminate polyphenols during DNA purification. In addition, omitting the selective precipitation and NaCl gradient steps in the extraction protocol, enabled us to extract DNA 10–20 min faster than the normal protocol. Of the tested microsatellite loci, 11 were successful in amplifying sharp and high-intensity bands in all the four multiplex panels and were polymorphic. The level of polymorphism ranged from 0.115 to 0.794, with a mean 0.50 and mean number of alleles varied from 2 to 10, with overall mean of 6 alleles per locus. The mean observed and expected heterozygosity ranged from 0.058 to 0.970 and 0.102 to 0.796, respectively. The 11 microsatellite loci that were effectively amplified from A. mearnsii DNA were adequate in detecting genetic variation among the tested populations.
 Conclusions: These PCR-based, multi-allelic, co-dominant microsatellite markers provide a powerful tool for genetic, breeding and conservation studies in A. mearnsii.

SILEX: a fast and inexpensive high-quality DNA extraction method suitable for multiple sequencing platforms and recalcitrant plant species

BackgroundThe use of sequencing and genotyping platforms has undergone dramatic improvements, enabling the generation of a wealth of genomic information. Despite this progress, the availability of high-quality genomic DNA (gDNA) in sufficient concentrations is often a main limitation, especially for third-generation sequencing platforms. A variety of DNA extraction methods and commercial kits are available. However, many of these are costly and frequently give either low yield or low-quality DNA, inappropriate for next generation sequencing (NGS) platforms. Here, we describe a fast and inexpensive DNA extraction method (SILEX) applicable to a wide range of plant species and tissues.ResultsSILEX is a high-throughput DNA extraction protocol, based on the standard CTAB method with a DNA silica matrix recovery, which allows obtaining NGS-quality high molecular weight genomic plant DNA free of inhibitory compounds. SILEX was compared with a standard CTAB extraction protocol and a common commercial extraction kit in a variety of species, including recalcitrant ones, from different families. In comparison with the other methods, SILEX yielded DNA in higher concentrations and of higher quality. Manual extraction of 48 samples can be done in 96 min by one person at a cost of 0.12 €/sample of reagents and consumables. Hundreds of tomato gDNA samples obtained with either SILEX or the commercial kit were successfully genotyped with Single Primer Enrichment Technology (SPET) with the Illumina HiSeq 2500 platform. Furthermore, DNA extracted from Solanum elaeagnifolium using this protocol was assessed by Pulsed-field gel electrophoresis (PFGE), obtaining a suitable size ranges for most sequencing platforms that required high-molecular-weight DNA such as Nanopore or PacBio.ConclusionsA high-throughput, fast and inexpensive DNA extraction protocol was developed and validated for a wide variety of plants and tissues. SILEX offers an easy, scalable, efficient and inexpensive way to extract DNA for various next-generation sequencing applications including SPET and Nanopore among others.

English

The extraction of high-quality DNA from okra (Abelmoschus esculentus L. Moench) is notoriously troublesome due to the high contents of polysaccharides, polyphenols, and different secondary metabolites. We have tested seven extraction buffers on silica dried okra leaves. Here, we describe a simple, rapid and modified procedure for high-quality DNA extraction from okra, which is amenable for downstream analyses. In contrast to Cetyl-trimethyl-ammonium bromide (CTAB) methods, the described procedure is rapid, omits the use of liquid nitrogen, phenol, PVP-10, and chloroform. It also uses inexpensive and less hazardous reagents and requires only ordinary laboratory equipment. The procedure employed a high concentration of Sodium dodecyl sulphate (SDS) to rid the problems associated with polysaccharides and polyphenols. The average yield was between 36 and 45 μg of total DNA from 90 mg of dried leaf weight. The DNA is adequate for molecular analysis of okra, such as genetic mapping or marker-assisted plant breeding. This protocol can be performed in as little as 3 h and may be adapted to high-throughput DNA isolation.   Key words: PVP-10, polyvinylpyrrolidone, non cetyltrimethylammonium bromide, okra, genomic DNA, Sodium dodecyl sulphate (SDS).

Extraction of high-quality genomic DNA and identification of different DNA barcoding markers for chickpea (Cicer arietinum L.)

The genetic studies of individual plants, especially self-pollinated species like chickpea need to be evaluated at the DNA level with the help of molecular markers for identifying genetic variations among the plants. High-quality DNA extraction is a prerequisite for genetic studies. Extraction of intact genomic DNA with high – molecular mass is essential for the study of many molecular biology applications like Polymerase Chain Reaction, endonuclease restriction digestion, southern blot analysis, and also for the construction of a genomic library. Several plant DNA extraction methods are available, even though the DNA isolation methods that give good yield employing both quantity and quality is quite difficult especially for self-pollinated crops like a chickpea. This work was focused on developing a standard protocol for the extraction of genomic DNA and identifying different barcoding markers. The result revealed that the CTAB extraction method with slight modification in protocol had been optimized for DNA isolation. The purified DNA, which was isolated through the CTAB method, had excellent spectral qualities and is efficiently digested by a restriction endonuclease, and is found to be more suitable for long-fragment PCR amplification. DNA barcoding is considered as a promising tool because it provides a practical and standard identification of plants. The isolated DNA sample was processed with a classical DNA barcoding approach by amplifying and sequencing with a universal primer. According to the result, among the different barcoding markers studied, the RbcL and Mat K were found to given the best result for molecular species identification in chickpea.

Evaluation of a Highly Efficient DNA Extraction Method for Bacillus anthracis Endospores.

A variety of methods have been established in order to optimize the accessibility of DNA originating from Bacillus anthracis cells and endospores to facilitate highly sensitive molecular diagnostics. However, most endospore lysis techniques have not been evaluated in respect to their quantitative proficiencies. Here, we started by systematically assessing the efficiencies of 20 DNA extraction kits for vegetative B. anthracis cells. Of these, the Epicentre MasterPure kit gave the best DNA yields and quality suitable for further genomic analysis. Yet, none of the kits tested were able to extract reasonable quantities of DNA from cores of the endospores. Thus, we developed a mechanical endospore lysis protocol, facilitating the extraction of high-quality DNA. Transmission electron microscopy or the labelling of spores with the indicator dye propidium monoazide was utilized to assess lysis efficiency. Finally, the yield and quality of genomic spore DNA were quantified by PCR and they were found to be dependent on lysis matrix composition, instrumental parameters, and the method used for subsequent DNA purification. Our final standardized lysis and DNA extraction protocol allows for the quantitative detection of low levels (<50 CFU/mL) of B. anthracis endospores and it is suitable for direct quantification, even under resource-limited field conditions, where culturing is not an option.

The Influence of DNA Extraction and Lipid Removal on Human Milk Bacterial Profiles.

Culture-independent molecular techniques have advanced the characterization of environmental and human samples including the human milk (HM) bacteriome. However, extraction of high-quality genomic DNA that is representative of the bacterial population in samples is crucial. Lipids removal from HM prior to DNA extraction is common practice, but this may influence the bacterial population detected. The objective of this study was to compare four commercial DNA extraction kits and lipid removal in relation to HM bacterial profiles. Four commercial DNA extraction kits, QIAamp® DNA Microbiome Kit, ZR Fungal/Bacterial DNA MiniPrep™, QIAsymphony DSP DNA Kit and ZymoBIOMICS™ DNA Miniprep Kit, were assessed using milk collected from ten healthy lactating women. The kits were evaluated based on their ability to extract high quantities of pure DNA from HM and how well they extracted DNA from bacterial communities present in a commercial mock microbial community standard spiked into HM. Finally, the kits were evaluated by assessing their extraction repeatability. Bacterial profiles were assessed using Illumina MiSeq sequencing targeting the V4 region of the 16S rRNA gene. The ZR Fungal/Bacterial DNA MiniPrep™ and ZymoBIOMICS™ DNA Miniprep (Zymo Research Corp., Irvine, CA, USA) kits extracted the highest DNA yields with the best purity. DNA extracted using ZR Fungal/Bacterial DNA MiniPrep™ best represented the bacteria in the mock community spiked into HM. In un-spiked HM samples, DNA extracted using the QIAsymphony DSP DNA kit showed statistically significant differences in taxa prevalence from DNA extracted using ZR Fungal/Bacterial DNA MiniPrep™ and ZymoBIOMICS™ DNA Miniprep kits. The only difference between skim and whole milk is observed in bacterial profiles with differing relative abundances of Enhydrobacter and Acinetobacter. DNA extraction, but not lipids removal, substantially influences bacterial profiles detected in HM samples, emphasizing the need for careful selection of a DNA extraction kit to improve DNA recovery from a range of bacterial taxa.

PCR Amplifiable DNA from Breast Disease FFPE Section for Mutational Analysis.

Formalin-fixed paraffin-embedded (FFPE) tissue specimens have been a staple of research, providing precious resources for molecular and genomic studies. However, the biggest challenge is the extraction of high-quality DNA from FFPE tissues, given that the integrity of DNA is critically affected by formalin fixation. Formaldehyde induces crosslinks in DNA that renders single or double-stranded DNA breaks. Such breaks cause extensive fragmentation that directly influences the quality of DNA purified and the number of templates available for PCR amplification. Thus, protocol for DNA purification from FFPE tissues must effectively extract highly fragmented DNA and reverse cross-linking caused by formalin fixation. DNA extraction methods available in the literature were selected and modified at different stages to optimize a protocol that extracts DNA of sufficient quality and fragment size to be detectable by PCR. Archived FFPE tissues belonged to patients with triple negative breast cancer (TNBC) and benign breast disease were used for the protocol optimization. The best optimized protocol was then used to amplify Exon 4 region of Proviral integration site for Moloney murine leukemia virus1 (Pim1) kinase gene to analyze any probable somatic mutations both in TNBCs and benign breast diseases. Of the 12 different protocols developed, best quality DNA in terms of fragment size and purity was obtained when Tween20 lysis buffer was used for both deparaffinization and overnight digestion along with high salt precipitation. Optimized protocol was then validated by extracting DNAs from 10 TNBCs and 5 benign breast disease specimens with consistent purity and fragment size. PCR amplification and subsequent Sanger's sequencing revealed the presence of mutations in the Exon 4 region of Pim1 kinase. Deparaffinization and overnight digestion in Tween20 lysis buffer along with high salt precipitation yielded the best quality PCR amplifiable DNA for mutational analysis.

A Modified SDS – Based Method Applied for Extraction of High-Quality DNA from Raw Corn and Roasted Soybean

Abstract The probability of contamination of non-transgenic varieties with genetically modified (GM) products increase as a result of global expansion of areas sown with transgenic crops. DNA-based methods as accurate, efficient and reliable methods are preferable for detection of GM material in raw or highly processed foods. Isolation of high quality DNA with a suitable and efficient DNA extraction protocol is crucial for getting precise results in DNA amplification. In this study, we performed modifications of previously known Sodium dodecyl sulfate (SDS)-based DNA extraction method regarding the incubation period, DNA pellet washing and addition of organic solvent extraction, to improve DNA quality and to reduce costs. Raw corn kernels and roasted soybean seed were used as samples. DNA was extracted following three protocols, modifications of Edwards protocol. The type of detergent used in raw corn sample did not cause significant effects on extracted DNA yield and purity, while in roasted soybean samples the 2% (w/v) SDS lysis buffer gave the highest DNA yield. The additional incubation step raised the DNA yield from raw corn for 121%, while the purest DNA from soybean sample was obtained using organic solvent extraction. Electrophoretic determination of DNA integrity showed varying degree of DNA smearing from roasted soybean. Contrary, all extraction protocols used on raw corn kernels produced a high molecular weight DNA. Thus, our in-house DNA extraction protocol is as efficient but more cost effective compared to commercial kits and can be used for raw corn, while the protocol for roasted soybean needs further improvement.

DNA extraction from archived hematoxylin and eosin-stained tissue slides for downstream molecular analysis.

BACKGROUNDHistopathologically stained archived tissue slides are stored in hospital archives for years to decades. They are the largest available source of biological materials and are a potentially useful resource that can be used for retrospective epidemiological studies. DNA recovered from the slides can be used for several downstream molecular processes including polymerase chain reaction, single nucleotide polymorphism analysis, and whole genome sequencing. The DNA from these slides can be utilized to compare gene signatures of normal and diseased tissues. However, extraction of high-quality DNA from archived stained hematoxylin and eosin (H&E) slides remains challenging.AIMTo standardize a new protocol for extracting DNA from archived H&E-stained tissue slides for further molecular assays.METHODSA total of 100 archived H&E-stained cancer slides were subjected to a total of five methods of DNA extraction. Methods were varied in the deparaffinization step, tissue rehydration, duration of lysis, and presence or absence of proteinase K. The extracted DNA was quantified using a NanoDrop spectrophometer and the quality was analyzed by agarose gel electrophoresis. Then each sample was subjected to polymerase chain reaction (PCR) to amplify the internal control gene GAPDH, thereby confirming the DNA intactness, which could be further utilized for other downstream applications.RESULTSOf the five different methods tested, the third method wherein xylene was used for tissue deparaffinization followed by 72 h of digestion and without proteinase K inactivation yielded the highest amount of DNA with good purity. The yield was significantly higher when compared to other methods. In addition, 90% of the extracted DNA showed amplifiable GAPDH gene.CONCLUSIONHere we present a step-by-step, cost-effective, and reproducible protocol for the extraction of PCR-friendly DNA from archived H&E-stained cancer tissue slides that can be used for further downstream molecular applications.

Based on magnetic beads to develop the kit for extraction of high-quality cell-free DNA from blood of breast cancer patients

Early detection of breast cancer (BC) is very important to avoid mortality caused by it. It is concluded in recent studies that the DNA in patient's serum can be used as biomarker for cancer detection. Therefore, extracting high-quality DNA from patient's serum can achieve this goal. In this work, we compared three methods (phenol-chloroform, column-based and magnetic beads) of extracting DNA from serum by means of purchased commercial kits and concluded that column-based kit is the best one to extract Cell-free DNA (cfDNA). Then we developed a new kit named PuriMag magnetic beads kit to extract DNA from serum of BC patients. Further, we described the properties of this new kit including its recovery capacity and stability. We compared the extraction performances of PuriMag magnetic beads kit and column-based kit and concluded that PuriMag magnetic beads are a better method to extract cfDNA. Surely PuriMag magnetic beads also suit automation and will be a useful method for fast, high-quality and automatic DNA extraction from serum.

Whole-Genome Bisulfite Sequencing and Epigenetic Variation in Cereal Methylomes.

Whole-genome bisulfite sequencing (WGBS) is a technique used for the analysis of genome-wide DNA methylation patterns (DNA methylomes) at a single-base resolution. Here, I describe a simple DNA extraction method from rice endosperm and the universal protocol of WGBS, MethylC-sequencing library preparation. The use of benzyl chloride allows for the extraction of high-quality genomic DNA from starchy endosperm, while sodium bisulfite converts unmethylated cytosine to uracil, whereas methylated cytosine is unchanged. The bisulfite conversion of whole genome sequencing libraries before the final amplification step allows for the discrimination of methylated from unmethylated cytosines in a genome-wide manner.

Modified CTAB method for high-quality genomic DNA extraction from ship barnacle (Balanus sp.)

Presence of high amount of polysaccharide and polyphenolic compounds in barnacles restricts the isolation of high molecular weight good quality DNA. CTAB, which is a detergent used to isolate DNA from high polysaccharide containing plants, is used in this study to extract quality DNA from ship barnacle. This modified CTAB method is simple, efficient and quick enough to be carried out within 2 h. Taking DNAzol ® isolated DNA as a reference, restriction digestion and PCR was performed to prove the absence of any enzyme inhibitory substances in the isolate. Traditional phenol-chloroform and salting out method failed to even isolate the DNA from barnacle sample. The molecular weight of the modified CTAB extracted DNA was higher than that of DNAzol ® extracted DNA which makes it better candidate for analyses like whole genome sequencing.