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QubitTM dsDNA HS Assay Kit

Qubit ® dsDNA HS Assay Kit

Company: Thermo Fisher Scientific
Catalog#: Q32854
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Coupling Exonuclease Digestion with Selective Chemical Labeling for Base-resolution Mapping of 5-Hydroxymethylcytosine in Genomic DNA
Author:
Date:
2018-03-05
[Abstract]  This protocol is designed to obtain base-resolution information on the level of 5-hydroxymethylcytosine (5hmC) in CpGs without the need for bisulfite modification. It relies on (i) the capture of hydroxymethylated sequences by a procedure known as ‘selective chemical labeling’ (see Szulwach et al., 2012) and (ii) the digestion of the captured DNA by exonucleases. After Illumina sequencing of the digested DNA fragments, an ad hoc bioinformatic pipeline extracts the information for further downstream analysis. [摘要]  该协议旨在获得CpGs中5-羟甲基胞嘧啶(5hmC)水平的碱基分辨率信息,而无需亚硫酸氢盐修饰。 它依赖于(i)通过称为“选择性化学标记”(参见Szulwach等人,2012)的方法捕获羟甲基化序列和(ii)通过外切核酸酶消化捕获的DNA。 在消化的DNA片段的Illumina测序之后,特设的生物信息学管道提取信息用于进一步的下游分析。

【背景】基因组DNA中胞嘧啶的甲基化可以被蛋白质读取,并且主要被翻译成基因沉默。基因组中的大多数CpG二核苷酸是甲基化的,包括位于基因调控区如增强子的那些。然而,当需要时,这些CpG可以通过Ten Eleven Translocation(TET)酶将甲基氧化并且通过碱基切除修复系统用未甲基化的胞嘧啶置换来去甲基化。 5-羟甲基胞嘧啶(5hmC)是5-甲基胞嘧啶的第一个氧化衍生物,并且在基因组中绘制该修饰的碱基提供了关于正在进行活性去甲基化的区域的信息。尽管选择性化学标记(SCL)可以非常特异地检测5hmC,但该技术的分辨率受DNA片段大小的限制,特别是当捕获的DNA中存在多个CpG时。为了提高分辨率,我们引入了使用外切核酸酶的消化步骤,所述核酸外切酶将DNA分子修剪成靠近羟甲基化的胞嘧啶(Sérandour et。,2016)。然后对测序读数进行适当的生物信息学处理,然后将羟甲基化评分赋予捕获的CpG。

A Small RNA Isolation and Sequencing Protocol and Its Application to Assay CRISPR RNA Biogenesis in Bacteria
Author:
Date:
2018-02-20
[Abstract]  Next generation high-throughput sequencing has enabled sensitive and unambiguous analysis of RNA populations in cells. Here, we describe a method for isolation and strand-specific sequencing of small RNA pools from bacteria that can be multiplexed to accommodate multiple biological samples in a single experiment. Small RNAs are isolated by polyacrylamide gel electrophoresis and treated with T4 polynucleotide kinase. This allows for 3’ adapter ligation to CRISPR RNAs, which don’t have pre-existing 3’-OH ends. Pre-adenylated adapters are then ligated using T4 RNA ligase 1 in the absence of ATP and with a high concentration of polyethylene glycol (PEG). The 3’ capture step enables precise determination of the 3’ ends of diverse RNA molecules. Additionally, a random hexamer in the ligated ... [摘要]  新一代高通量测序技术能够对细胞中的RNA群体进行敏感和明确的分析。在这里,我们描述了一种从细菌中分离和链特异性测序小RNA池的方法,所述细菌可以在单个实验中多路复用以容纳多个生物样品。小RNA通过聚丙烯酰胺凝胶电泳分离并用T4多核苷酸激酶处理。这允许3'衔接头连接至CRISPR RNA,其不具有预先存在的3'-OH末端。然后使用T4 RNA连接酶1在不存在ATP和高浓度聚乙二醇(PEG)的情况下将前腺苷酸化的衔接子连接。 3'捕获步骤能够精确测定不同RNA分子的3'末端。此外,连接适配器中的随机六聚体有助于控制潜在的下游扩增偏差。逆转录后,将cDNA产物环化并通过PCR制备文库。我们显示扩增的文库不需要通过凝胶电泳可见,以期望产物的有效测序。使用这种方法,我们通常从少量纯化的小RNA制备RNA测序文库。该协议适合于通过对成熟的CRISPR RNA进行测序来测定细菌中的CRISPR RNA生物合成,但可以用于测序不同类型的小RNA。我们还提供了一个完整的数据处理管道示例,并提供了运行所提供脚本的说明。


【背景】与聚集的经常散布的短回文重复序列(CRISPR)相关的遗传模块赋予不同的原核宿主适应性免疫(Barrangou et ...

Adapting the Smart-seq2 Protocol for Robust Single Worm RNA-seq
Author:
Date:
2018-02-20
[Abstract]  Most nematodes are small worms that lack enough RNA for regular RNA-seq protocols without pooling hundred to thousand of individuals. We have adapted the Smart-seq2 protocol in order to sequence the transcriptome of an individual worm. While developed for individual Steinernema carpocapsae and Caenorhabditis elegans larvae as well as embryos, the protocol should be adaptable for other nematode species and small invertebrates. In addition, we describe how to analyze the RNA-seq results using the Galaxy online environment. We expect that this method will be useful for the studying gene expression variances of individual nematodes in wild type and mutant backgrounds. [摘要]  大多数线虫是小蠕虫,缺乏足够的RNA用于常规的RNA-seq协议,而没有汇集成千上万的个体。 我们已经调整了Smart-seq2协议来排序单个蠕虫的转录组。 虽然针对Steinernema carpocapsae和Caenorhabditis elegans幼虫以及胚胎开发,但该方案应该适用于其他线虫物种和小无脊椎动物。 另外,我们介绍如何使用Galaxy在线环境分析RNA-seq结果。 我们预计这种方法将有助于研究野生型和突变体背景个体线虫的基因表达差异。

【背景】低输入RNA-seq方案和扩增试剂盒,例如Smart-seq(Takara Bio,USA,Inc)和SuperAmp(Miltenyl Biotec,Inc),已经越来越多地开发和商业化,作为对低输入RNA-基于小组织,单一微生物和单细胞的seq研究。这些研究经常探索并解决特定群体(例如细胞群体,复杂组织或微生物群体)的个体中的异源基因表达。针对微生物(如线虫)的低输入RNA-seq方案的改进和适应将通过允许在单一线虫水平上分析基因表达异质性而极大地有益于线虫领域。在这里,我们已经调整了单细胞RNA-seq方案Smart-seq2(Picelli等人,2013和2014; Trombetta等人,2014),对于单线虫RNA测序。我们成功地在昆虫寄生线虫Steinernema ...

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