ABSTRACT: High-throughput DNA extraction and cost-effective miniaturized metagenome and amplicon library preparation of soil samples for DNA sequencing
Project description:Library preparation for whole genome bisulphite sequencing (WGBS) is challenging due to side effects of the bisulphite treatment, which leads to extensive DNA damage. Recently, a new generation of methods for bisulphite sequencing library preparation have been devised. They are based on initial bisulphite treatment of the DNA, followed by adaptor tagging of single stranded DNA fragments, and enable WGBS using low quantities of input DNA. In this study, we present a novel approach for quick and cost effective WGBS library preparation that is based on splinted adaptor tagging (SPLAT) of bisulphite-converted single-stranded DNA. Moreover, we validate SPLAT against three commercially available WGBS library preparation techniques, two of which are based on bisulphite treatment prior to adaptor tagging and one is a conventional WGBS method.
Project description:Despite the precipitous decline in the cost of genome sequencing over the last few years, library preparation for RNA-seq is still laborious and expensive for high throughput screening for drug discovery. Limited availability of RNA generated by some experimental workflows poses an additional challenge and typically adds to the cost of RNA library preparation. In a search for low cost, automation-compatible RNA library preparation kits that also maintain strand specificity and are amenable to low input RNA quantities, we systematically tested two recent commercial technologies – Swift and Swift Rapid – using the Illumina TruSeq stranded mRNA, the de facto standard workflow for bulk transcriptomics, as our reference. We used the Universal Human Reference RNA (UHRR) (composed of equal quantities of total RNA from 10 human cancer cell lines) to benchmark differential gene expression in these kits, at input quantities ranging between 10 ng to 500 ng. Read quality and alignment metrics revealed high mapping efficiency and uniform read coverage through genes for all samples across all three kits. Normalized read counts between all treatment groups were in high agreement, with pairwise Pearson correlation coefficients >0.97. Compared to the Illumina TruSeq stranded mRNA kit, both Swift RNA library kits are cost effective and offer shorter workflow times enabled by their patented Adaptase technology. Furthermore, the Swift RNA kit allows for a relatively broader (and lower) input range, producing consistent results across diverse samples. The Swift Rapid RNA method is the fastest and most cost effective NGS workflow that is best suited for higher RNA yields, with the exact same RNA input range as the Illumina TruSeq kit. We also found the Swift RNA kit to produce the fewest number of differentially expressed genes and pathways attributable to input mRNA concentration.
Project description:Here, we report the development of two RNA-seq library preparation protocols that increase the throughput and decrease the cost of converting RNA to cDNA libraries compatible for sequencing on high-throughput platforms. BaM-seq allows for early barcoding of samples such that many biological samples can be processed simultaneously. TBaM-seq allows for enrichment of target RNAs to decrease the required sequencing depth. Both methods are able to accurately measure gene expression changes with high technical reproducibility and agreement with gold standard, lower throughput approaches.
Project description:Here, we report the development of two RNA-seq library preparation protocols that increase the throughput and decrease the cost of converting RNA to cDNA libraries compatible for sequencing on high-throughput platforms. BaM-seq allows for early barcoding of samples such that many biological samples can be processed simultaneously. TBaM-seq allows for enrichment of target RNAs to decrease the required sequencing depth. Both methods are able to accurately measure gene expression changes with high technical reproducibility and agreement with gold standard, lower throughput approaches.
2023-02-01 | GSE206423 | GEO
Project description:Contamination from amplicon library preparation
Project description:We have engineered the thermostable KlenTaq DNA polymerase variant called RIV A8 that produces error signatures specific for 5-methylcytosine (5mC) and 5-hydroxycytosine (5hmC) without prior chemical treatment of the DNA samples. These signatures are amplified during DNA amplicon library preparation and are detected by NGS. This method was applied to distinguish C from 5mC and C from 5hmC in DNA templates generated by PCR using modified dCTPs (unmodified by using dCTP, methylated by using d5mCTP, hydroxymethylated by using d5hmCTP).
Project description:<p>Next generation sequencing has aided characterization of genomic variation. While whole genome sequencing may capture all possible mutations, whole exome sequencing is more cost-effective and captures most phenotype-altering mutations. Initial strategies for exome enrichment utilized a hybridization-based capture approach. Recently, amplicon-based methods were designed to simplify preparation and utilize smaller DNA inputs. We appraised two hybridization capture-based and two amplicon-based whole exome sequencing methods, utilizing both Illumina and Ion Torrent sequencers, comparing on-target alignment, uniformity, and variant calling. While the amplicon methods had higher on-target rates, the hybridization capture-based approaches showed better uniformity. All methods identified many of the same single nucleotide variants, but each amplicon-based method missed variants detected by the other three methods and reported additional variants discordant with all three other technologies. Many of these potential false positives or negatives appear to result from limited coverage, low variant frequency, vicinity to read starts/ends, or the need for platform-specific variant calling algorithms. All methods demonstrated effective copy number variant calling when compared against a single nucleotide polymorphism array. This study illustrates some differences between various whole exome sequencing approaches, highlights the need for selecting appropriate variant calling based on capture method, and will aid laboratories in selecting their preferred approach.</p>