scholarly journals Choice of DNA extraction method affects DNA metabarcoding of unsorted invertebrate bulk samples

2018 ◽  
Vol 2 ◽  
Author(s):  
Markus Majaneva ◽  
Ola H. Diserud ◽  
Shannon H.C. Eagle ◽  
Mehrdad Hajibabaei ◽  
Torbjørn Ekrem

Characterisation of freshwater benthic biodiversity using DNA metabarcoding may allow more cost-effective environmental assessments than the current morphological-based assessment methods. DNA metabarcoding methods where sorting or pre-sorting of samples are avoided altogether are especially interesting, since the time between sampling and taxonomic identification is reduced. Due to the presence of non-target material like plants and sediments in crude samples, DNA extraction protocols become important for maximising DNA recovery and sample replicability. We sampled freshwater invertebrates from six river and lake sites and extracted DNA from homogenised bulk samples in quadruplicate subsamples, using a published method and two commercially available kits: HotSHOT approach, Qiagen DNeasy Blood & Tissue Kit and Qiagen DNeasy PowerPlant Pro Kit. The performance of the selected extraction methods was evaluated by measuring DNA yield and applying DNA metabarcoding to see if the choice of DNA extraction method affects DNA yield and metazoan diversity results. The PowerPlant Kit extractions resulted in the highest DNA yield and a strong significant correlation between sample weight and DNA yield, while the DNA yields of the Blood & Tissue Kit and HotSHOT method did not correlate with the sample weights. Metazoan diversity measures were more repeatable in samples extracted with the PowerPlant Kit compared to those extracted with the HotSHOT method or the Blood & Tissue Kit. Subsampling using Blood & Tissue Kit and HotSHOT extraction failed to describe the same community in the lake samples. Our study exemplifies that the choice of DNA extraction protocol influences the DNA yield as well as the subsequent community analysis. Based on our results, low specimen abundance samples will likely provide more stable results if specimens are sorted prior to DNA extraction and DNA metabarcoding, but the repeatability of the DNA extraction and DNA metabarcoding results was close to ideal in high specimen abundance samples.

2003 ◽  
Vol 25 (2) ◽  
pp. 83-88 ◽  
Author(s):  
Hans Jürgen Grote ◽  
Viola Schmiemann ◽  
Mario Sarbia ◽  
Alfred Böcking

Objective: To date, there are only few systematic reports on the quality of DNA extracted from routine diagnostic cytologic specimens. It was the aim of the present study to evaluate the ability of 50% ethanol/2% carbowax (Saccomanno fixative) to preserve bronchial secretions with high quality genomic DNA as well as to compare different DNA extraction methods.Methods: DNA was extracted from 45 bronchial aspirates by four different extraction protocols. Beside DNA yield, DNA quality with regard to purity, integrity, and PCR success rate were investigated.Results: No fragmentation of sample DNA due to the fixative was detected. It was preserved as high molecular weight DNA. DNA yield, purity, and integrity were dependent on the DNA extraction method to some extend. Irrespective of the DNA extraction method the PCR success rate for amplification of β‐globin gene fragments (268, 536, and 989 bp) was 100%. Conclusions: A fixative containing 50% ethanol/2% carbowax preserves high quality DNA which is well suited for PCR‐based assays regardless of the extraction protocol used. The selection of the DNA extraction protocol has to be adjusted to the circumstances of application.


2020 ◽  
Vol 5 (2) ◽  
pp. 95 ◽  
Author(s):  
Rajashree Chowdhury ◽  
Prakash Ghosh ◽  
Md. Anik Ashfaq Khan ◽  
Faria Hossain ◽  
Khaledul Faisal ◽  
...  

To detect Post-kala-azar leishmaniasis (PKDL) cases, several molecular methods with promising diagnostic efficacy have been developed that involve complicated and expensive DNA extraction methods, thus limiting their application in resource-poor settings. As an alternative, we evaluated two rapid DNA extraction methods and determined their impact on the detection of the parasite DNA using our newly developed recombinase polymerase amplification (RPA) assay. Skin samples were collected from suspected PKDL cases following their diagnosis through national guidelines. The extracted DNA from three skin biopsy samples using three different extraction methods was subjected to RPA and qPCR. The qPCR and RPA assays exhibited highest sensitivities when reference DNA extraction method using Qiagen (Q) kit was followed. In contrast, the sensitivity of the RPA assay dropped to 76.7% and 63.3%, respectively, when the boil & spin (B&S) and SpeedXtract (SE) rapid extraction methods were performed. Despite this compromised sensitivity, the B&S-RPA technique yielded an excellent agreement with both Q-qPCR (k = 0.828) and Q-RPA (k = 0.831) techniques. As expected, the reference DNA extraction method was found to be superior in terms of diagnostic efficacy. Finally, to apply the rapid DNA extraction methods in resource-constrained settings, further methodological refinement is warranted to improve DNA yield and purity through rigorous experiments.


2019 ◽  
Vol 39 (2) ◽  
Author(s):  
Yimiao Xia ◽  
Fusheng Chen ◽  
Yan Du ◽  
Chen Liu ◽  
Guanhao Bu ◽  
...  

Abstract Soybean is the most important genetically modified (GM) oilseed worldwide. Regulations relating to the approval of biotech soybean varieties and product labeling demand accurate and reliable detection techniques to screen for GM soya. High-quality extracted DNA is essential for DNA-based monitoring methods. Thus, four widely used protocols (SDS, CTAB, DP305, and DNeasy Plant Mini Kit) were compared in the present study to explore the most efficient DNA extraction method for raw soya matrix. The SDS-based method showed the highest applicability. Then crucial factors influencing DNA yield and purity, such as SDS lysis buffer component concentrations and organic compounds used to isolate DNA, were further investigated to improve the DNA obtained from raw soybean seeds, which accounts for the innovation of this work. As a result, lysis buffer (2% SDS (w/v), 150 mM NaCl, 50 mM Tris/HCl, 50 mM EDTA, pH 8.0) and organic reagents including chloroform/isoamyl alcohol (24:1, v/v) (C: I), isopropanol, and ethanol corresponding to the extraction and first and second precipitation procedures, respectively, were used in the optimized SDS method. The optimized method was verified by extracting approximately 2020–2444 ng DNA/mg soybean with A260/280 ratios of 1.862–1.954 from five biotech and non-biotech soybean varieties. Only 0.5 mg of soya was required to obtain enough DNA for PCR amplification using the optimized SDS-based method. These results indicate that the screening protocol in the present study achieves the highest suitability and efficiency for DNA isolation from raw soya seed flour.


2019 ◽  
Author(s):  
Q.R. Ducarmon ◽  
B.V.H. Hornung ◽  
A.R. Geelen ◽  
E.J. Kuijper ◽  
R.D. Zwittink

ABSTRACTWhen studying the microbiome using next generation sequencing, DNA extraction method, sequencing procedures and bioinformatic processing are crucial to obtain reliable data. Method choice has been demonstrated to strongly affect the final biological interpretation. We assessed the performance of three DNA extraction methods and two bioinformatic pipelines for bacterial microbiota profiling through 16S rRNA gene amplicon sequencing, using positive and negative controls for DNA extraction and sequencing, and eight different types of high- or low-biomass samples. Performance was evaluated based on quality control passing, DNA yield, richness, diversity and compositional profiles. All DNA extraction methods retrieved the theoretical relative bacterial abundance with maximum three-fold change, although differences were seen between methods, and library preparation and sequencing induced little variation. Bioinformatic pipelines showed different results for estimating richness, but diversity and compositional profiles were comparable. DNA extraction methods were successful for feces and oral swabs and variation induced by DNA extraction methods was lower than inter-subject (biological) variation. For low-biomass samples, a mixture of genera present in negative controls and sample-specific genera, possibly representing biological signal, were observed. We conclude that the tested bioinformatic pipelines perform equally with pipeline-specific advantages and disadvantages. Two out of three extraction methods performed equally well, while one method was less accurate regarding retrieval of compositional profiles. Lastly, we demonstrate the importance of including negative controls when analyzing low bacterial biomass samples.IMPORTANCEMethod choice throughout the workflow of a microbiome study, from sample collection to DNA extraction and sequencing procedures, can greatly affect results. This study evaluated three different DNA extraction methods and two bioinformatic pipelines by including positive and negative controls, and various biological specimens. By identifying an optimal combination of DNA extraction method and bioinformatic pipeline use, we hope to contribute to increased methodological consistency in microbiome studies. Our methods were not only applied to commonly studied samples for microbiota analysis, e.g. feces, but also for more rarely studied, low-biomass samples. Microbiota composition profiles of low-biomass samples (e.g. urine and tumor biopsies) were not always distinguishable from negative controls, or showed partial overlap, confirming the importance of including negative controls in microbiome studies, especially when low bacterial biomass is expected.


OENO One ◽  
2013 ◽  
Vol 47 (4) ◽  
pp. 227 ◽  
Author(s):  
Gemma Marsal ◽  
Núria Boronat ◽  
Joan Miquel Canals ◽  
Fernando Zamora ◽  
Francesca Fort

<p style="text-align: justify;"><strong>Aim</strong>: To compare different methods for extracting DNA from non-recalcitrant and recalcitrant tissues of <em>Vitis vinifera</em> woody plants and propose a modification of a previously published method to reduce the time and cost of extraction.</p><p style="text-align: justify;"><strong>Methods and results</strong>: DNA was extracted from young and mature leaves as well as from stems and seeds using some of the most common methods of DNA isolation and two commercial kits. Another commercial kit, which does not require DNA extraction prior to PCR, was also used. Only two methods provided adequate results in all tissues. Other methods were only applicable to some tissues and some did not yield any functional DNA in any tissue. A modification of the method reported by Marsal <em>et al</em>. (2011) is proposed to reduce handling time and cost.</p><p style="text-align: justify;"><strong>Conclusion</strong>: All of the methods studied here use a surfactant to improve the extractions. For DNA extraction from recalcitrant tissues to be optimal, it is best to use a combination of dodecyltrimethylammonium bromide (DTAB) and cetyltrimethylammonium bromide (CTAB). The changes made to the protocol reported by Marsal <em>et al</em>. (2011) enable functional DNA to be obtained from leaves in only 90 minutes and at very low cost (17 €/8 samples). However, this method cannot adequately isolate DNA from recalcitrant tissues (stems and seeds) and so, for this type of sample, we would recommend using the original method.</p><p style="text-align: justify;"><strong>Significance and impact of the study</strong>: Nowadays, handling time and cost are key factors in selecting the most suitable DNA extraction method. This study compares not only the effectiveness of the various methods but also the handling time and cost. It also proposes a modification of the fastest and most economic DNA extraction method for leaves so that handling time and processing cost will be reduced even further.</p>


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Anthony Ablordey ◽  
Evans Ahotor ◽  
Charles A. Narh ◽  
Sandra A. King ◽  
Isra Cruz ◽  
...  

Abstract Background Early diagnosis and treatment of Buruli ulcer is critical in order to avoid the debilitating effects of the disease. In this regard, the development of new diagnostic and point of care tools is encouraged. The loop-mediated isothermal amplification for the detection of Mycobacterium ulcerans represents one of the new tools with a good potential of being developed into a point of care test. There is however the need to standardize the assays, reduce sample preparation times, improve the detection/visualization system and optimize them for high-throughput screening, adaptable to low resourced laboratories. Methods In this study, we assessed two DNA extraction protocols (modified Boom and EasyNAT methods), three previously published LAMP primer sets (BURULI, MU 2404 and BU-LAMP), and compared the sensitivity and specificity of LAMP assays on three DNA amplification platforms. Results Our results show that Buruli ulcer diagnosis using primers targeting IS2404 for the LAMP method is sensitive (73.75–91.49%), depending on the DNA extraction method used. Even though the modified Boom DNA extraction method provided the best results, its instrumentation requirement prevent it from being field applicable. The EasyNAT method on the other hand is simpler and may represent the best method for DNA extraction in less resourced settings. Conclusions For further work on the development and use of LAMP tests for Buruli diagnosis, it is recommended that the BURULI sets of primers be used, as these yielded the best results in terms of sensitivity (87.50–91.49%) and specificity (89.23–100%), depending on the DNA extraction methods used.


2021 ◽  
Author(s):  
Rachel L. Byrne ◽  
Derek Cocker ◽  
Ghaith Alyayyoussi ◽  
Madalitso Mphasa ◽  
Mary Charles ◽  
...  

ABSTRACTBackgroundEnvironmental water samples are increasingly recognised as an important reservoir of antimicrobial resistance (AMR) genes. Polymerase chain reaction (PCR) and next generation sequencing (NGS) offer a potentially inclusive surveillance platform for a wide range of AMR genes. However, molecular methods are dependent upon the extraction of DNA of high yield and quality. Current options for DNA extraction from complex environmental matrices for downstream molecular applications are either expensive or low yielding. We present here a novel magnetic bead-based DNA extraction method, for the detection of antimicrobial resistance genes (ARGs) from river water in Malawi, named MagnaExtract.MethodsMagnaExtract involves initial filtration of 250ml freshwater, followed by an overnight incubation of the filter in 15ml buffered peptone water (BPW), common procedure in microbiology laboratories. 200µl is then taken for a boil (95°C) and spin step and mixed with magnetic beads to bind DNA. Following washes with ethanol, the DNA is eluted in nuclease-free water. To determine the effectiveness of this method, 98 freshwater samples were collected from two rivers in Southern Malawi, and DNA was isolated using the MagnaExtract method, two commercial Qiagen (Germany) kits; PowerWater and DNeasy Blood and tissue, alongside a boil and spin of BPW, and a boil and spin from bacterial isolate grown on agar media. All samples were screened with a high-resolution melt (HRM) PCR panel previously validated for the detection of third generation cephalosporin and carbapenem ARGs. We compared the DNA yield obtained using all extraction methods, as well as the identification of each ARG.ResultsDNA yield using MagnaExtract was statistically greater than both boil and spin methods and DNeasy Blood & Tissue (Qiagen, Germany). DNA yield was slightly lower than using PowerWater (Qiagen) but the difference was not statistically significant. MagnaExtract was the only method to identify ARGs in all 98 water samples compared with PowerWater (n=82), DNeasy (n=95) boilate of BPW (n=75) and boilate of bacterial isolate (n=87). The most commonly detected ARG was OXA-48 (n=93). In addition, we found overnight incubation in non-selective enrichment broth (BPW) to promote the growth of bacteria harbouring extended spectrum beta lactamase (ESBL) genes and reduction in the detection of carbapenemase genes.ConclusionThe MagnaExtract approach offers a simple, affordable, high yielding DNA extraction method for the detection of ARGs isolated from river water samples.


2021 ◽  
Vol 7 (3) ◽  
pp. 304-319
Author(s):  
Spyridon Andreas Papatheodorou ◽  
◽  
Panagiotis Halvatsiotis ◽  
Dimitra Houhoula ◽  

<abstract> <p>Foodborne infections continue to plague Europe. Food safety monitoring is in crisis as the existing techniques for detecting pathogens do not keep up with the global rising of food production and consumption. Thus, the development of innovative techniques for detecting and identifying pathogenic bacteria has become critical. The aim of the present study was firstly to develop an innovative simple and low cost method of extracting bacterial DNA from contaminated food and water samples with <italic>Salmonella enteric</italic> subsp. <italic>enteric</italic> serovar Typhimurium and <italic>Listeria monocytogenes</italic> and its comparison with two commercial DNA extraction kits (Qiagen, Macherey-Nagel). Finally, pathogens' detection using two molecular techniques (PCR-electrophoresis, LAMP), in order to evaluate the best combination of DNA extraction and identification based on their sensitivity, cost, rapidity and simplicity. Considering the above criteria, among them, best was proved an in-house bacterial DNA extraction method, based on the chloroform-isoamyl alcohol protocol, with certain modifications. This technique showed statistically similar results in terms of sensitivity, compared to the commercial kits, while at the same time maintained high rapidity and much lower cost. Lastly, between the molecular techniques, LAMP was found more promising considering its simplicity, high rapidity and sensitivity. Conclusively, the in-house DNA extraction method along with the LAMP technique, was proven to be the best among the presented combinations.</p> </abstract>


mSystems ◽  
2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Q. R. Ducarmon ◽  
B. V. H. Hornung ◽  
A. R. Geelen ◽  
E. J. Kuijper ◽  
R. D. Zwittink

ABSTRACT When studying the microbiome using next-generation sequencing, the DNA extraction method, sequencing procedures, and bioinformatic processing are crucial to obtain reliable data. Method choice has been demonstrated to strongly affect the final biological interpretation. We assessed the performance of three DNA extraction methods and two bioinformatic pipelines for bacterial microbiota profiling through 16S rRNA gene amplicon sequencing, using positive and negative controls for DNA extraction and sequencing and eight different types of high- or low-biomass samples. Performance was evaluated based on quality control passing, DNA yield, richness, diversity, and compositional profiles. All DNA extraction methods retrieved the theoretical relative bacterial abundance with a maximum 3-fold change, although differences were seen between methods, and library preparation and sequencing induced little variation. Bioinformatic pipelines showed different results for observed richness, but diversity and compositional profiles were comparable. DNA extraction methods were successful for feces and oral swabs, and variation induced by DNA extraction methods was lower than intersubject (biological) variation. For low-biomass samples, a mixture of genera present in negative controls and sample-specific genera, possibly representing biological signal, were observed. We conclude that the tested bioinformatic pipelines perform equally, with pipeline-specific advantages and disadvantages. Two out of three extraction methods performed equally well, while one method was less accurate regarding retrieval of compositional profiles. Lastly, we again demonstrate the importance of including negative controls when analyzing low-bacterial-biomass samples. IMPORTANCE Method choice throughout the workflow of a microbiome study, from sample collection to DNA extraction and sequencing procedures, can greatly affect results. This study evaluated three different DNA extraction methods and two bioinformatic pipelines by including positive and negative controls and various biological specimens. By identifying an optimal combination of DNA extraction method and bioinformatic pipeline use, we hope to contribute to increased methodological consistency in microbiota studies. Our methods were applied not only to commonly studied samples for microbiota analysis, e.g., feces, but also to more rarely studied, low-biomass samples. Microbiota composition profiles of low-biomass samples (e.g., urine and tumor biopsy specimens) were not always distinguishable from negative controls, or showed partial overlap, confirming the importance of including negative controls in microbiota studies, especially when low bacterial biomass is expected.


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