这项工作的一部分是由核心项目 (赠款 41/11)、以色列科学基金会 (908/15 号赠款) 和欧洲克罗恩病组织 (ECCO) 支持。

该研究的伦理批准是由示巴地方研究伦理学委员会批准的, 所有方法都是按照相关的指导方针和条例进行的。该议定书收到了当地道德审查委员会的病人同意例外, 因为使用的粪便材料已经作为临床检查的一部分提交给微生物学核心, 而没有其他人的年龄以外的可识别的病人信息,性别和微生物结果。从健康志愿者那里获得书面、知情的同意, 机构审查委员会批准了这项研究。其中一些示例已包含在以前的分析1中。
1. 样品处理
<ol><li>收集一个大约5毫米2涂片 (大致大小的铅笔橡皮擦) 从一个新鲜的粪便样本与无菌拭子在试管 (见材料表)。将含有粪便样品的所有拭子贮存在24小时内-80 摄氏度。粪便拭子可以留在那里, 直到进一步处理。</li>
</ol>2. DNA 提取
<ol><li>在室温下解冻萃取和稀释液 (请参阅材料表)。</li>
	<li>将粪便拭子转移到空的2毫升收集管 (请参阅材料表)。通过使用干净的剪刀来调整拭子棒的尺寸, 以使管道闭合时具有最小的交叉污染。加入 250 ul 的萃取液, 每个收集管含有粪便拭子和漩涡混合。</li>
	<li>在沸腾的水浴中加热样品10分钟 (95–100°c).添加 250 ul 稀释溶液的每个样品和涡流混合。</li>
	<li>储存2毫升的管含有提取的 DNA 和拭子在4摄氏度。</li>
</ol>3. PCR 和图书馆准备
对于步骤3.1 和 3.2, 在提供干净、模板和扩增子自由环境的 PCR 工作站中工作。
<ol><li>根据其条码标记底漆 (表 1)。将双蒸馏水 (DDW) 中的每一底漆稀释至50微米浓度, 并贮存在-20 摄氏度。</li>
	<li>用96井板进行 PCR 反应。每个盘子可以包含32不同的样品, 由32个不同的索引引物标记。在室温下解冻前底漆和32反向底漆, 稀释至5微米。</li>
	<li>准备 pcr 反应混合100反应 (每个井的最终体积将是 20 ul) 混合 100 ul 的5微米前底漆, 1 毫升 2X PCR 主混合, 和 400 ul DDW。把这个 PCR 混合在每个井 (总共96口井) 15 ul。将每5微米反向索引底漆的 1 ul 添加到3个不同的井 (triplicates 中32种不同的引物, 总共提供96个井)。</li>
	<li>在预 PCR 专用区, 这意味着一个干净的长凳, 是模板和扩增子免费, 添加 4 ul 的每一个提取的 dna 样本到反应混合物 (每个提取的 dna 样本被放大32个样本每 96-井板)。</li>
	<li>运行 PCR 与以下设置: 初始变性94°c 3 分钟;其次35周期变性在94°c 为1分钟, 退火在55°c 为1分钟和延长在72°c 为1分钟;和最后的延伸在72°c 为10分钟。</li>
	<li>在一个不同的长凳上, 这将被定义为后 pcr 专用区, 结合每三个 pcr 反应成一个单一的容积管 (60 ul 每样品)。</li>
	<li>为了评估 pcr amplicons 的质量, 在溴溴染色的1% 琼脂糖凝胶上, 对每个联合 pcr 反应运行 4 ul。在紫外波长为 260 nm 的情况下, 正 amplicons 将出现在预期的 375–425 bp 波段大小。只有这些 amplicons 将包含在后续步骤中。 注: 每样样品都有三份放大, 这意味着每个样品在3种不同的 PCR 反应中被放大。不要放大。</li>
</ol>4. 图书馆量化和清洁
<ol><li>为了获得所有 PCR 样品的摩尔浓度池, 用双链 DNA (dsDNA 定量试剂) 荧光灯核酸染色 (参见材料表) 量化每个扩增子, 适合于同时量化大型样本量。 注: 由于扩增子的尺寸范围是模棱两可的, 毫微克的实际用量用于加载摩尔浓度。</li>
	<li>将每个样品的 500 ng 组合成一个单一的无菌管。漩涡混合。</li>
	<li>在一个溴溴染色的1% 琼脂糖凝胶上运行 200 ul 的汇集图书馆。根据制造商的说明 (请参阅材料表) 并洗脱 80 ul DDW 中的汇集库, 从凝胶中提取 375–425 bp 带。 注: 池库应选择大小, 以减少来自宿主 DNA 的非特定放大产品。</li>
	<li>根据制造商的说明, 使用高度敏感的 dsDNA 检测套件测量最终库浓度 (请参阅材料表)。根据制造商的说明, 使用对 DNA 库的高度敏感的分离和分析工具包测量准确的库大小 (请参阅材料表)。</li>
</ol>5. 测序
<ol><li>根据顺序机协议, 将池库稀释到下午7点, 并添加20% 控制库 (参见材料表)。</li>
	<li>对于排序, 使用自定义的 V4 放大引物免费的读引物 (请参见表 1)。</li>
	<li>根据制造商的规范, 使用第三个自定义的测序底漆, 在附加周期中读取条形码 (请参见表 1), 并在每个方向上生成175个基的配对端读取。</li>
	<li>根据制造商的协议, 运行顺序机并获取 FASTQ 文件。</li>
</ol>6. 数据处理
<ol><li>在 QIIME 2 版 2017.7. 017中实现的数据精选管线中, 缝合并处理重叠的配对端 FASTQ 文件。根据示例特定的条形码解读取。</li>
	<li>使用 DADA218进行质量控制和序列变体 (SVs) 检测。将读取从 3 ' 端和15个基点从 5 ' 端截断13个基元, 丢弃超过2个预期错误的读取。使用协商一致方法识别和删除合体-合体分别在样本中检测到, 并且在样本的足够部分中发现嵌合体的序列被删除。</li>
	<li>使用朴素的贝叶斯拟合分类器执行 SVs 分类分类, 在 2013年8月99% 标识 Greengenes 数据库6上进行培训, 用于175长时间读取和正/反向底漆集。</li>
	<li>Rarefy 所有样本的深度为2146个序列。</li>
	<li>在稀薄的样品上使用加权 UniFrac 测量β多样性 (样品多样性19,20), 以避免样本大小的影响。</li>
	<li>使用所得到的距离矩阵来执行主坐标分析 (PCoA)。 注意: 数据处理脚本和映射文件作为补充材料提供 (辅助材料 1和2)。</li>
</ol>

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作者没有什么可透露的。

16S rRNA-扩增子和 metagenomics 猎枪测序在临床微生物学应用中得到了普及21, 2223.这些技术有利于提高捕获可培养和非可培养类群的能力, 提供有关致病接种的相对丰度的数据, 以及它们识别更精确的 polymicrobial 传染性的能力。指纹24。微生物研究领域的进展产生了大量的数据, 由于各种方法缺乏一致性, 因此难以比较。最近几年, 一些财团试...

为了更好地了解微生物的多样性和丰度, 已作出了集中努力, 作为在健康和病理条件下捕捉个体差异和相似性的另一个方面。年龄2,3, 地理4, 生活方式5,6, 疾病5被证明与肠道微生物组的组成有关, 但许多条件和人口尚未完全特点.最近据报道, 微生物菌群可以被修改为治疗性应用7,8,9。因此, 进一步了解各种生理条件和微生物组成之间的关系, 是迈向优化未来潜在的修改的第一步。
传统的微生物培养方法受低产量的限制10,11, 并被概念化为一个二进制状态, 其中细菌是存在于肠道或没有。高通量 DNA 测序已经彻底改变了微生物生态学, 使微生物群落的所有成员都能被捕获。但是, 序列读取长度和质量仍然是精确分类分配12的重要障碍。此外, 基于高通量的实验可能会受到批处理效果的影响, 其中测量受非生物或非科学变量13的影响。近年来, 已经建立了一些研究人类微生物菌群的方案, 包括美国肠道项目、美国 (美国) 人类微生物学项目和联合王国 (英国) MetaHIT 项目。这些倡议产生了大量的数据, 由于它们的做法缺乏连贯性, 因此难以比较。各种国际项目, 如国际人类微生物菌群联合会、国际人类微生物菌群标准项目以及国家标准和技术研究所 (NIST) 试图解决其中的一些问题14, 并制定了微生物菌群测量标准, 这将有助于实现可靠的生殖结果。这里描述的是一些广泛使用的方法15、16的集成协议, 用于 16S rRNA 高通量测序 (十六年代序列), 从粪便样本收集通过数据分析开始。该议定书描述了一种无柱 PCR 方法, 最初设计用于直接提取植物 DNA16, 以便在相对较短的时间内同时处理大量的粪便样本, 并以高质量的扩增 DNA 为靶向常规测序平台上微生物变量 V4 区域的测序。该议定书的目的是引导感兴趣的科学家开始使用 16S rRNA 扩增子测序, 在健壮, 生殖, 易于使用, 详细的方式, 使用重要的控制。具有引导和详细的分步协议可能会减少批处理效果, 从而允许在实验室之间进行更可比较的排序结果。

<table>
	<tbody>
		<tr>
			<td>Primers</td>
			<td>Integrated DNA Technologies (IDT)</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Extraction solution</td>
			<td>Sigma-Aldrich</td>
			<td>E7526</td>
			<td></td>
		</tr>
		<tr>
			<td>Dilution solution</td>
			<td>Sigma-Aldrich</td>
			<td>D5688</td>
			<td></td>
		</tr>
		<tr>
			<td>Kapa HiFi HotStart ReadyMix PCR Kit</td>
			<td>KAPABIOSYSTEMS</td>
			<td>KK2601</td>
			<td>PCR Master mix</td>
		</tr>
		<tr>
			<td>Quant-iT PicoGreen dsDNA Reagent kit</td>
			<td>Invitrogen</td>
			<td>P7589</td>
			<td>dsDNA quantify reagent</td>
		</tr>
		<tr>
			<td>MinElute Gel extraction kit</td>
			<td>Qiagen</td>
			<td>28606</td>
			<td></td>
		</tr>
		<tr>
			<td>Agarose</td>
			<td>Amresco</td>
			<td>0710-250G</td>
			<td></td>
		</tr>
		<tr>
			<td>Ultra Pure Water Dnase and Rnase Free</td>
			<td>Biological Industries</td>
			<td>01-866-1A</td>
			<td></td>
		</tr>
		<tr>
			<td>Qubit dsDNA HS assay kit</td>
			<td>Molecular probes</td>
			<td>Q32854</td>
			<td>dsDNA detecting kit</td>
		</tr>
		<tr>
			<td>High Sensitivity D1000</td>
			<td>Agilent Technologies</td>
			<td>Screen Tape 5067-5582</td>
			<td>separation and analysis</td>
		</tr>
		<tr>
			<td>Screen Tape Assay</td>
			<td>Agilent Technologies</td>
			<td>Reagents 5067-5583</td>
			<td>for DNA libraries</td>
		</tr>
		<tr>
			<td>PhiX Control v3</td>
			<td>Illumina</td>
			<td>15017666</td>
			<td>control library</td>
		</tr>
		<tr>
			<td>MiSeq Reagent Kit v2 (500 cycle)</td>
			<td>Illumina</td>
			<td>MS-102-2003</td>
			<td></td>
		</tr>
		<tr>
			<td>Ethidium Bromide</td>
			<td>Amresco</td>
			<td>E406-10mL-TAM</td>
			<td></td>
		</tr>
		<tr>
			<td>2 mL collection tubes</td>
			<td>SARSTEDT</td>
			<td>72.695.400</td>
			<td>Safe Seal collection tubes</td>
		</tr>
		<tr>
			<td>Plastic stick swab in PP test tube</td>
			<td>STERILE INTERIOR</td>
			<td>23117</td>
			<td></td>
		</tr>
		<tr>
			<td>Name</td>
			<td>Company</td>
			<td>Catalog Number</td>
			<td>Comments</td>
		</tr>
		<tr>
			<td>Equipment</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>PCR Machine</td>
			<td>Applied Biosystems</td>
			<td>2720 Thermal Cycler</td>
			<td></td>
		</tr>
		<tr>
			<td>Sequncing Machine</td>
			<td>Illumina</td>
			<td>Miseq</td>
			<td></td>
		</tr>
		<tr>
			<td>PCR workstation</td>
			<td>Biosan</td>
			<td>UV-cleaner</td>
			<td></td>
		</tr>
		<tr>
			<td>scissors</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>vortexer</td>
			<td>Scientific Industries</td>
			<td>Vortex-Genie 2</td>
			<td></td>
		</tr>
	</tbody>
</table>

guided protocol for fecal microbial characterization by 16s rrna-amplicon sequencing

人体肠道菌群在保护细胞免遭伤害、处理能量和养分以及促进免疫力方面起着重要作用。从被认为是健康的微生物组成 (dysbiosis) 的偏差可能会损害导致病理状况的重要功能。最近和正在进行的研究工作已被用于描述微生物组成与人类健康和疾病之间的关联。
高通量测序技术的进展使肠道微生物成分的特征得以表征。这些方法包括 16S rRNA 扩增子测序和猎枪测序。16S rRNA 扩增子测序用于分析分类成分, 而猎枪测序则提供有关基因预测和功能注释的附加信息。使用 16S rRNA 基因可变区的目标测序方法的优点是它的成本与猎枪测序相比大大降低。在 16S rRNA 基因中的序列差异被用作微生物指纹, 用来识别和量化个体样本中不同的分类群。
主要的国际努力已登记了 16S rRNA 扩增子测序标准。然而, 一些研究报告了一个常见的变异来源, 由间歇效应引起。为了最小化这种效果, 必须实现示例收集、处理和排序的统一协议。该协议提出了从粪便样本采集开始到数据分析的广泛应用协议的集成。该协议包括无列的直接 pcr 方法, 能够同时处理和 DNA 提取大量粪便样本, 以及 V4 区域的 PCR 扩增。此外, 该协议描述分析管道, 并提供一个脚本使用最新版本的 QIIME (QIIME 2 版 2017.7. 0 和 DADA2)。这一步步协议的目的是引导那些感兴趣的人开始使用 16S rRNA 扩增子测序的健壮, 繁殖, 易于使用, 详细的方式。

该协议的示意图说明显示在图 1中。
我们有前瞻性收集的粪便样本, 从住院病人疑似传染性腹泻。这些样本是在2月至2015年5月期间提交给示巴医疗中心的临床微生物学实验室的, 如前所述的1。粪便标本在临床微生物学实验室进行常规微生物培养, 并在十六年代平行的范围内进行广泛的高?...

Watch this Scientific Journal Video about Guided Protocol for Fecal Microbial Characterization by 16S rRNA-Amplicon Sequencing at JoVE.com

Guided Protocol for Fecal Microbial Characterization by 16S rRNA-Amplicon Sequencing

这篇手稿描述了一个详细的标准化协议高通量 16S rRNA 扩增子测序。该协议引入了一个集成的, 统一的, 可行的, 廉价的协议, 从粪便样本收集, 通过数据分析。该协议允许分析大量的样本, 严格的标准和几个控制。

16S rRNA-扩增子测序法对粪便微生物特性的指导协议

The human intestinal microbiome plays a central role in protecting cells from injury, in processing energy and nutrients, and in promoting immunity. ...

guided-protocol-for-fecal-microbial-characterization-16s-rrna

Research

JoVE Journal

Biology

19.4K 次观看.  Sheba Medical Center. 这篇手稿描述了一个详细的标准化协议高通量 16S rRNA 扩增子测序。该协议引入了一个集成的, 统一的, 可行的, 廉价的协议, 从粪便样本收集, 通过数据分析。该协议允许分析大量的样本, 严格的标准和几个控制。

视频: Guided Protocol for Fecal Microbial Characterization by 16S rRNA-Amplicon Sequencing

Pyrosequencing for Microbial Identification and Characterization

Pyrosequencing is a versatile technique that facilitates microbial genome sequencing that can be used to identify bacterial species, discriminate bacterial strains and detect genetic mutations that confer resistance to anti-microbial agents. The advantages of pyrosequencing for microbiology applications include rapid and reliable high-throughput screening and accurate identification of microbes and microbial genome mutations. Pyrosequencing involves sequencing of DNA by synthesizing the complementary strand a single base at a time, while determining the specific nucleotide being incorporated during the synthesis reaction. The reaction occurs on immobilized single stranded template DNA where the four deoxyribonucleotides (dNTP) are added sequentially and the unincorporated dNTPs are enzymatically degraded before addition of the next dNTP to the synthesis reaction. Detection of the specific base incorporated into the template is monitored by generation of chemiluminescent signals. The order of dNTPs that produce the chemiluminescent signals determines the DNA sequence of the template. The real-time sequencing capability of pyrosequencing technology enables rapid microbial identification in a single assay. In addition, the pyrosequencing instrument, can analyze the full genetic diversity of anti-microbial drug resistance, including typing of SNPs, point mutations, insertions, and deletions, as well as quantification of multiple gene copies that may occur in some anti-microbial resistance patterns.

Pyrosequencing is a versatile technique that facilitates microbial genome sequencing that can be used to identify bacterial species, discriminate bacterial strains, and detect genetic mutations that confer resistance to anti-microbial agents. In this video, the procedure for microbial amplicon generation, amplicon pyrosequencing, and DNA sequence analysis will be demonstrated.

焦磷酸测序的微生物鉴定和表征

Pyrosequencing is a versatile technique that facilitates microbial genome sequencing that can be used to identify bacterial species, discriminate ...

科研

生物学

In Vivo 4-Dimensional Tracking of Hematopoietic Stem and Progenitor Cells in Adult Mouse Calvarial Bone Marrow

Through a delicate balance between quiescence and proliferation, self renewal and production of differentiated progeny, hematopoietic stem cells (HSCs) maintain the turnover of all mature blood cell lineages. The coordination of the complex signals leading to specific HSC fates relies upon the interaction between HSCs and the intricate bone marrow microenvironment, which is still poorly understood[1-2].
We describe how by combining a newly developed specimen holder for stable animal positioning with multi-step confocal and two-photon in vivo imaging techniques, it is possible to obtain high-resolution 3D stacks containing HSPCs and their surrounding niches and to monitor them over time through multi-point time-lapse imaging. High definition imaging allows detecting ex vivo labeled hematopoietic stem and progenitor cells (HSPCs) residing within the bone marrow. Moreover, multi-point time-lapse 3D imaging, obtained with faster acquisition settings, provides accurate information about HSPC movement and the reciprocal interactions between HSPCs and stroma cells.
Tracking of HSPCs in relation to GFP positive osteoblastic cells is shown as an exemplary application of this method. This technique can be utilized to track any appropriately labeled hematopoietic or stromal cell of interest within the mouse calvarium bone marrow space.

In Vivo 4-Dimensional Tracking of Hematopoietic Stem and Progenitor Cells in Adult Mouse Calvarial Bone Marrow

The nature of the interactions between hematopoietic stem and progenitor cells (HSPCs) and bone marrow niches is poorly understood. Custom hardware modifications and a multi-step acquisition protocol allow the use of two-photon and confocal microscopy to image ex vivo labeled HSPCs homed within bone marrow areas, tracking interactions and movement.

在造血干细胞和祖细胞的成年小鼠颅骨骨髓体内四维跟踪

Through a delicate balance between quiescence and proliferation, self renewal and production of differentiated progeny, hematopoietic stem cells (HSCs) ...

Next-generation Sequencing of 16S Ribosomal RNA Gene Amplicons

One of the major questions in microbial ecology is &#8220;who is there?&#8221; This question can be answered using various tools, but one of the long-lasting gold standards is to sequence 16S ribosomal RNA (rRNA) gene amplicons generated by domain-level PCR reactions amplifying from genomic DNA. Traditionally, this was performed by cloning and Sanger (capillary electrophoresis) sequencing of PCR amplicons. The advent of next-generation sequencing has tremendously simplified and increased the sequencing depth for 16S rRNA gene sequencing. The introduction of benchtop sequencers now allows small labs to perform their 16S rRNA sequencing in-house in a matter of days. Here, an approach for 16S rRNA gene amplicon sequencing using a benchtop next-generation sequencer is detailed. The environmental DNA is first amplified by PCR using primers that contain sequencing adapters and barcodes. They are then coupled to spherical particles via emulsion PCR. The particles are loaded on a disposable chip and the chip is inserted in the sequencing machine after which the sequencing is performed. The sequences are retrieved in fastq format, filtered and the barcodes are used to establish the sample membership of the reads. The filtered and binned reads are then further analyzed using publically available tools. An example analysis where the reads were classified with a taxonomy-finding algorithm within the software package Mothur is given. The method outlined here is simple, inexpensive and straightforward and should help smaller labs to take advantage from the ongoing genomic revolution.

Characterizing microbial community has been a longstanding goal in environmental microbiology. Next-generation sequencing methods now allow for the characterization of microbial communities at an unprecedented depth with minimal cost and labor. We detail here our approach to sequence bacterial 16S ribosomal RNA genes using a benchtop sequencer.

的16S核糖体RNA基因的扩增子的新一代测序

One of the major questions in microbial ecology is &#8220;who is there?&#8221; This question can be answered using various tools, but one of the ...

Highly Efficient Ligation of Small RNA Molecules for MicroRNA Quantitation by High-Throughput Sequencing

MiRNA cloning and high-throughput sequencing, termed miR-Seq, stands alone as a transcriptome-wide approach to quantify miRNAs with single nucleotide resolution. This technique captures miRNAs by attaching 3&#8217; and 5&#8217; oligonucleotide adapters to miRNA molecules and allows de novo miRNA discovery. Coupling with powerful next-generation sequencing platforms, miR-Seq has been instrumental in the study of miRNA biology. However, significant biases introduced by oligonucleotide ligation steps have prevented miR-Seq from being employed as an accurate quantitation tool. Previous studies demonstrate that biases in current miR-Seq methods often lead to inaccurate miRNA quantification with errors up to 1,000-fold for some miRNAs1,2. To resolve these biases imparted by RNA ligation, we have developed a small RNA ligation method that results in ligation efficiencies of over 95% for both 3&#8217; and 5&#8242; ligation steps. Benchmarking this improved library construction method using equimolar or differentially mixed synthetic miRNAs, consistently yields reads numbers with less than two-fold deviation from the expected value. Furthermore, this high-efficiency miR-Seq method permits accurate genome-wide miRNA profiling from in vivo total RNA samples2.

MicroRNAs (miRNAs) are a widely conserved class of regulatory molecules. Here we describe a miRNA cloning method that relies upon two potent ligation steps followed by high-throughput sequencing. Our method permits accurate genome-wide quantitation of miRNAs.

小RNA分子的高效结扎的微小RNA定量高通量测序

MiRNA cloning and high-throughput sequencing, termed miR-Seq, stands alone as a transcriptome-wide approach to quantify miRNAs with single nucleotide ...

Targeted DNA Methylation Analysis by Next-generation Sequencing

The role of epigenetic processes in the control of gene expression has been known for a number of years. DNA methylation at cytosine residues is of particular interest for epigenetic studies as it has been demonstrated to be both a long lasting and a dynamic regulator of gene expression. Efforts to examine epigenetic changes in health and disease have been hindered by the lack of high-throughput, quantitatively accurate methods. With the advent and popularization of next-generation sequencing (NGS) technologies, these tools are now being applied to epigenomics in addition to existing genomic and transcriptomic methodologies. For epigenetic investigations of cytosine methylation where regions of interest, such as specific gene promoters or CpG islands, have been identified and there is a need to examine significant numbers of samples with high quantitative accuracy, we have developed a method called Bisulfite Amplicon Sequencing (BSAS). This method combines bisulfite conversion with targeted amplification of regions of interest, transposome-mediated library construction and benchtop NGS. BSAS offers a rapid and efficient method for analysis of up to 10 kb of targeted regions in up to 96 samples at a time that can be performed by most research groups with basic molecular biology skills. The results provide absolute quantitation of cytosine methylation with base specificity. BSAS can be applied to any genomic region from any DNA source. This method is useful for hypothesis testing studies of target regions of interest as well as confirmation of regions identified in genome-wide methylation analyses such as whole genome bisulfite sequencing, reduced representation bisulfite sequencing, and methylated DNA immunoprecipitation sequencing.

Bisulfite amplicon sequencing (BSAS) is a method for quantifying cytosine methylation in targeted genomic regions of interest. This method uses bisulfite conversion paired with PCR amplification of target regions prior to next-generation sequencing to produce absolute quantitation of DNA methylation at a base-specific level.

有针对性的DNA甲基化分析通过新一代测序

The role of epigenetic processes in the control of gene expression has been known for a number of years. DNA methylation at cytosine residues is of ...

Isolation of Specific Genomic Regions and Identification of Associated Molecules by enChIP

The identification of molecules associated with specific genomic regions of interest is required to understand the mechanisms of regulation of the functions of these regions. To enable the non-biased identification of molecules interacting with a specific genomic region of interest, we recently developed the engineered DNA-binding molecule-mediated chromatin immunoprecipitation (enChIP) technique. Here, we describe how to use enChIP to isolate specific genomic regions and identify the associated proteins and RNAs. First, a genomic region of interest is tagged with a transcription activator-like (TAL) protein or a clustered regularly interspaced short palindromic repeats (CRISPR) complex consisting of a catalytically inactive form of Cas9 and a guide RNA. Subsequently, the chromatin is crosslinked and fragmented by sonication. The tagged locus is then immunoprecipitated and the crosslinking is reversed. Finally, the proteins or RNAs that are associated with the isolated chromatin are subjected to mass spectrometric or RNA sequencing analyses, respectively. This approach allows the successful identification of proteins and RNAs associated with a genomic region of interest.

The identification of molecules associated with specific genomic regions of interest is required to understand the mechanisms of regulation of the functions of these regions. This protocol describes procedures to perform engineered DNA-binding molecule-mediated chromatin imunoprecipitation (enChIP) for identification of proteins and RNAs associated with a specific genomic region.

具体的基因组区域及相关分子鉴定enChIP隔离

The identification of molecules associated with specific genomic regions of interest is required to understand the mechanisms of regulation of the ...

Fecal Glucocorticoid Analysis: Non-invasive Adrenal Monitoring in Equids

Adrenal activity can be assessed in the equine species by analysis of feces for corticosterone metabolites. During a potentially aversive situation, corticotrophin releasing hormone (CRH) is released from the hypothalamus in the brain. This stimulates the release of adrenocorticotrophic hormone (ACTH) from the pituitary gland, which in turn stimulates release of glucocorticoids from the adrenal gland. In horses the glucocorticoid corticosterone is responsible for several adaptations needed to support equine flight behaviour and subsequent removal from the aversive situation. Corticosterone metabolites can be detected in the feces of horses and assessment offers a non-invasive option to evaluate long term patterns of adrenal activity. Fecal assessment offers advantages over other techniques that monitor adrenal activity including blood plasma and saliva analysis. The non-invasive nature of the method avoids sampling stress which can confound results. It also allows the opportunity for repeated sampling over time and is ideal for studies in free ranging horses. This protocol describes the enzyme linked immunoassay (EIA) used to assess feces for corticosterone, in addition to the associated biochemical validation.

Adrenal activity can be assessed in the equine species by analysis of feces for corticosterone metabolites. The method offers a non-invasive option to assess long term patterns in both domestic and free ranging horses. This protocol describes the enzyme linked immunoassay involved and the associated biochemical validation.

糖皮质激素粪分析:在马属动物无创监测肾上腺

Adrenal activity can be assessed in the equine species by analysis of feces for corticosterone metabolites. During a potentially aversive situation, ...

Efficient Nucleic Acid Extraction and 16S rRNA Gene Sequencing for Bacterial Community Characterization

There is a growing appreciation for the role of microbial communities as critical modulators of human health and disease. High throughput sequencing technologies have allowed for the rapid and efficient characterization of bacterial communities using 16S rRNA gene sequencing from a variety of sources. Although readily available tools for 16S rRNA sequence analysis have standardized computational workflows, sample processing for DNA extraction remains a continued source of variability across studies. Here we describe an efficient, robust, and cost effective method for extracting nucleic acid from swabs. We also delineate downstream methods for 16S rRNA gene sequencing, including generation of sequencing libraries, data quality control, and sequence analysis. The workflow can accommodate multiple samples types, including stool and swabs collected from a variety of anatomical locations and host species. Additionally, recovered DNA and RNA can be separated and used for other applications, including whole genome sequencing or RNA-seq. The method described allows for a common processing approach for multiple sample types and accommodates downstream analysis of genomic, metagenomic and transcriptional information.

We describe an efficient, robust, and cost effective method for extracting nucleic acid from swabs for characterization of bacterial communities using 16S rRNA gene amplicon sequencing. The method allows for a common processing approach for multiple sample types and accommodates a number of downstream analytic processes.

高效的核酸提取和16S rRNA基因序列的细菌群落特征

There is a growing appreciation for the role of microbial communities as critical modulators of human health and disease. High throughput sequencing ...

A Protocol for Functional Assessment of Whole-Protein Saturation Mutagenesis Libraries Utilizing High-Throughput Sequencing

Site-directed mutagenesis has long been used as a method to interrogate protein structure, function and evolution. Recent advances in massively-parallel sequencing technology have opened up the possibility of assessing the functional or fitness effects of large numbers of mutations simultaneously. Here, we present a protocol for experimentally determining the effects of all possible single amino acid mutations in a protein of interest utilizing high-throughput sequencing technology, using the 263 amino acid antibiotic resistance enzyme TEM-1 &#946;-lactamase as an example. In this approach, a whole-protein saturation mutagenesis library is constructed by site-directed mutagenic PCR, randomizing each position individually to all possible amino acids. The library is then transformed into bacteria, and selected for the ability to confer resistance to &#946;-lactam antibiotics. The fitness effect of each mutation is then determined by deep sequencing of the library before and after selection. Importantly, this protocol introduces methods which maximize sequencing read depth and permit the simultaneous selection of the entire mutation library, by mixing adjacent positions into groups of length accommodated by high-throughput sequencing read length and utilizing orthogonal primers to barcode each group. Representative results using this protocol are provided by assessing the fitness effects of all single amino acid mutations in TEM-1 at a clinically relevant dosage of ampicillin. The method should be easily extendable to other proteins for which a high-throughput selection assay is in place.

We present a protocol for the functional assessment of comprehensive single-site saturation mutagenesis libraries of proteins utilizing high-throughput sequencing. Importantly, this approach uses orthogonal primer pairs to multiplex library construction and sequencing. Representative results using TEM-1 &#946;-lactamase selected at a clinically relevant dosage of ampicillin are provided.

经过一蛋白饱和诱变图书馆的功能评价规范利用高通量测序

Site-directed mutagenesis has long been used as a method to interrogate protein structure, function and evolution. Recent advances in massively-parallel ...

Interactome-Seq: A Protocol for Domainome Library Construction, Validation and Selection by Phage Display and Next Generation Sequencing

Folding reporters are proteins with easily identifiable phenotypes, such as antibiotic resistance, whose folding and function is compromised when fused to poorly folding proteins or random open reading frames. We have developed a strategy where, by using TEM-1 &#946;-lactamase (the enzyme conferring ampicillin resistance) on a genomic scale, we can select collections of correctly folded protein domains from the coding portion of the DNA of any intronless genome. The protein fragments obtained by this approach, the so called &#34;domainome&#34;, will be well expressed and soluble, making them suitable for structural/functional studies.
By cloning and displaying the &#34;domainome&#34; directly in a phage display system, we have showed that it is possible to select specific protein domains with the desired binding properties (e.g., to other proteins or to antibodies), thus providing essential experimental information for gene annotation or antigen identification.
The identification of the most enriched clones in a selected polyclonal population can be achieved by using novel next-generation sequencing technologies (NGS). For these reasons, we introduce deep sequencing analysis of the library itself and the selection outputs to provide complete information on diversity, abundance and precise mapping of each of the selected fragment. The protocols presented here show the key steps for library construction, characterization, and validation.

The protocols described allow the construction, characterization and selection (against the target of choice) of a &#34;domainome&#34; library made from any DNA source. This is achieved by a research pipeline that combines different technologies: phage display, a folding reporter and next generation sequencing with a web tool for data analysis.

Interactome: Domainome 图书馆建设、噬菌体展示和下一代测序的验证与选择协议

Folding reporters are proteins with easily identifiable phenotypes, such as antibiotic resistance, whose folding and function is compromised when fused to ...