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ABSTRACT:
PROVIDER: PRJNA430884 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Zhao et al. Amplification Table 3 This experiment was designed to evaluate the effect of ligase used in the second strand cDNA synthesis on the fidelity of T7 based RNA linear amplification. BC2 total RNA was amplified with or without ligase using Affymetrix protocol. Set of arrays organized by shared biological context, such as organism, tumors types, processes, etc. Computed
2005-11-03 | E-GEOD-3561 | biostudies-arrayexpress
Project description:This SuperSeries is composed of the following subset Series: GSE3557: Effect of the amount of input total RNA on T7 amplification GSE3558: Effect of in vitro transcription time on the fidelity of T7-based RNA linear amplification GSE3559: Variation in cDNA microarray analysis of gene expression using unamplified poly(A)+ RNA GSE3560: Effects of template switching (TS) primer and cDNA cleanup columns on T7 based RNA linear amplification GSE3561: Effect of ligase on T7 based RNA linear amplification GSE3562: Effect of column cleanup on T7 based RNA linear amplification GSE3563: Correlation between expression levels of different tumors measured by poly(A)+RNA and aRNA Abstract: BACKGROUND: T7 based linear amplification of RNA is used to obtain sufficient antisense RNA for microarray expression profiling. We optimized and systematically evaluated the fidelity and reproducibility of different amplification protocols using total RNA obtained from primary human breast carcinomas and high-density cDNA microarrays. RESULTS: Using an optimized protocol, the average correlation coefficient of gene expression of 11,123 cDNA clones between amplified and unamplified samples is 0.82 (0.85 when a virtual array was created using repeatedly amplified samples to minimize experimental variation). Less than 4% of genes show changes in expression level by 2-fold or greater after amplification compared to unamplified samples. Most changes due to amplification are not systematic both within one tumor sample and between different tumors. Amplification appears to dampen the variation of gene expression for some genes when compared to unamplified poly(A)+ RNA. The reproducibility between repeatedly amplified samples is 0.97 when performed on the same day, but drops to 0.90 when performed weeks apart. The fidelity and reproducibility of amplification is not affected by decreasing the amount of input total RNA in the 0.3-3 micrograms range. Adding template-switching primer, DNA ligase, or column purification of double-stranded cDNA does not improve the fidelity of amplification. The correlation coefficient between amplified and unamplified samples is higher when total RNA is used as template for both experimental and reference RNA amplification. CONCLUSION: T7 based linear amplification reproducibly generates amplified RNA that closely approximates original sample for gene expression profiling using cDNA microarrays. Refer to individual Series
2006-03-06 | E-GEOD-4349 | biostudies-arrayexpress
Project description:The use of RNA-seq as the preferred method for the discovery and validation of small RNA biomarkers is hindered by high variability and biased sequence counts. In this paper we develop a statistical model for sequence counts that accounts for ligase bias and stochastic variation in library amplification steps and sequencing depth variation. Our analytical contributions are the description of the Linear Quadratic (LQ) relation between the mean and variance of the sequence counts in an RNA-seq experiment and the derivation of the Poisson truncated mixture as the underlying probability distribution for RNA-seq data. Using a large number of sequencing datasets, we demonstrate here how one can use this modeling framework to calculate empirical correction factors for ligase bias, while accounting for random variation in sequence counts. Bias correction may remove the majority of bias in the absence of differential expression and more than 40% of the bias in the presence of variable expression of miRNAs. Empirical bias correction factors appear to be nearly constant over at least one and up to four orders of magnitude of total RNA input and independent of sample composition.
2017-03-15 | GSE93399 | GEO
Project description:The ligation step in RNA sequencing library generation is a known source of bias. We present the first comparison of the standard duplex adaptor protocol supplied by Life Technologies for use on the Ion Torrent PGM with an alternate single adaptor approach involving CircLigase (CircLig). We also investigate whether using the thermostable ligase Methanobacterium thermoautotrophicum RNA ligase K97A (Mth K97A) for the initial ligation step in the CircLigase protocol reduces bias. A pool of small RNA fragments of known composition was converted into a sequencing library using one of three protocols and sequenced on an Ion Torrent PGM. The single adaptor CircLigase-based approach significantly reduces, but does not eliminate, bias in Ion Torrent data. Using Mth K97A as part of the CircLig method does not further reduce bias.
2014-06-24 | E-MTAB-2566 | biostudies-arrayexpress
Project description:Zhao et al. Amplification Table 3 This experiment was designed to evaluate the effect of ligase used in the second strand cDNA synthesis on the fidelity of T7 based RNA linear amplification. BC2 total RNA was amplified with or without ligase using Affymetrix protocol. Set of arrays organized by shared biological context, such as organism, tumors types, processes, etc. Keywords: Logical Set
2005-11-04 | GSE3561 | GEO
Project description:We describe a novel indexing protocol that employs the activities of terminal DNA transferase and T4 DNA ligase to add unique cell barcodes to DNase-digested DNA ends. This protocol allows profiling of genome-wide DHSs in over 10,000 single-cells in an individual experiment.
2022-08-26 | GSE136987 | GEO
Project description:The molecular basis for the female bias of systemic lupus erythematosus remains unclear. We sought to determine the fidelity of dynamic X-chromosome inactivation maintenance in the pathogenesis of murine models of spontaneous lupus, including the heavily female-biased NZM2328 model.
2022-09-20 | GSE213318 | GEO
Project description:Purpose: we aimed to gain a genome-wide view of the dynamics in DNA methylation inheritance and define the factors associated with methylation fidelity. Methods: Using mouse embryonic stem cell (ES-E14TG2a) in both undifferentiated and differentiated states as a model system, we exploited the hairpin bisulfite sequencing approach to generate methylation data for DNA double strands simultaneously at single-base resolution. We generated the genome-wide hairpin bisulfite sequencing data to capture the methylation pattern variation during the stem cell transition from self-renewal to commitment, and integrated with various M-bM-^@M-^\omicsM-bM-^@M-^] data to scrutinize the relationships among DNA methylation inheritance, gene expression, histone modification, transcriptional factor binding and distribution of 5-hydroxylmethylation cytosine. Results and conclusion: Our results indicated that DNA methylation fidelity increases globally during early mouse embryonic stem cell differentiation. Methylation fidelity is remarkably high in promoter regions of actively expressed genes and positively correlated with active histone modification marks and binding of transcriptional factors. Strikingly, methylation fidelity follows a bimodal distribution for the intermediately methylated CpG dyads. In addition, the methylation difference in between two DNA strands rather than different DNA molecules is a major source of the intermediate DNA methylation. Lastly, while 5-hmC and 5-mC tend to coexist, no significant increase in the pairing with unmethylated cytosine was observed. For mouse embryonic stem cell of undifferentiated and spontaneous differentiated states, we determined DNA double strands methylation pattern by hairpin bisulfite sequencing approach and determined gene expression profiles using RNA-seq.
2014-05-12 | E-GEOD-48229 | biostudies-arrayexpress
Project description:Genome-wide profiling of transcription factors based on massive parallel sequencing of immunoprecipitated chromatin (ChIP-seq) requires nanogram amounts of DNA. Here we describe a high-fidelity, single-tube linear DNA amplification method (LinDA) for ChIP-seq and reChIP-seq with picogram DNA amounts obtained from a few thousand cells. This amplification technology will facilitate global analyses of transcription-factor binding and chromatin with very small cell populations, such as stem or cancer-initiating cells.
2011-10-11 | GSE32332 | GEO