我们感谢查尔斯·皮诺、梅兰妮·拉加里格和雷吉斯·拉维涅在植物样本的MALDI成像样品准备方面的技巧和技巧。

1. 样品准备
<ol><li>获取生物样本，要么保持新鲜和完好无损（例如，不要强迫它进入管子），要么将其冻结。拟议的协议适用于任何类型的固体生物样本（即植物、动物或人体组织），以本地化特定组织中的化合物。</li>
	<li>冷却低温微分到-20°C。 将样品支架和刀片保持在相同的温度下。</li>
	<li>如有必要，将对象嵌入 M1 嵌入介质中，以便在切割过程中保存它。<ol>
<li>将一些基质倒入放置在低温微分室的塑料模具中。快速添加样品，并倒入一些更多的嵌入介质，以覆盖它。当基质凝固并冷却时，将样品保持在模具中心。 注:并非所有生物物体都需要嵌入。同质物体，如老鼠的大脑不需要嵌入介质，可以切割冻结。</li>
	</ol>
</li>
	<li>将嵌入式或冷冻样品放在低温微分架上，用锋利的刀片切割。5-30 μm 的厚度对植物样本有好处，由于植物样本的异质性，这些样品很难切割。将切割厚度和温度调整到样品中，进行多次切割以找到最佳条件。在提供的示例中，样本被切割为 -20 °C。 考虑将样品保持在 0 °C 以下，以避免样品退化。 注意:使用放置在低温显微镜旁边的双目显微镜可以帮助确定切片的质量。组织必须完好无损。</li>
	<li>使用钳子或小画笔小心地将切片移到 ITO 涂层的滑梯上，然后将手指放在滑梯下，以加热和干燥样品。将幻灯片保存在冷冻微分室中，直到所有样品都准备好。慢慢将滑梯从房间中滑出，以避免热冲击。 注意:要检查幻灯片的哪一侧涂有 ITO 涂层，请在室温 （RT） 下在幻灯片上放置一滴水。掉落将停留在 ITO 涂层侧或未涂层侧的扁平上。</li>
	<li>使用薄记号笔或校正液在幻灯片上绘制标记，并在矩阵沉积前使用高分辨率扫描仪扫描。当样品在质谱仪中时，这些标记将用于确定样品在幻灯片上的确切位置。获得精确参照点的最佳方法是绘制十字架。</li>
</ol>2. 矩阵沉积
<ol><li>准备MALDI矩阵:重70毫克的α-氰诺-4-羟基辛酸（HCCA）基质，并稀释在10mL的水和甲醇溶液（50:50）与0.2%TFA。在RT将矩阵固化10分钟。声波化后可能有额外的固体矩阵。 注:根据感兴趣的分析，可以使用不同类型的 MALDI 矩阵。</li>
	<li>用100%甲醇清洁基质沉积机器人。</li>
	<li>使用甲醇和精密擦拭，清洁滑梯，保持样品不接触他们，不删除痕迹。在没有样品的区域中，在幻灯片上添加干净的盖片。然后将幻灯片的这一部分放置在光学探测器上以跟踪矩阵沉积。 注意:要光学跟踪矩阵厚度，滑梯和盖片必须非常干净。</li>
	<li>使用机器人进行矩阵沉积:在储层中只放置 6 mL 的基质溶液，并添加 2 mL 的 100% 甲醇，总容量为 8 mL。 注:沿沉积的矩阵厚度记录是自动的，可以使用 USB 棒恢复。喷洒方法的开发在这里没有详细说明。</li>
</ol>3. 数据获取
<ol><li>将矩阵的 1μL 放在 MALDI 板上，以使用矩阵峰值作为参考来校准质谱仪。质谱仪采集方法的开发情况没有详细说明。<ol>
<li>将 MALDI 板插入源中，单击 ftms 控制软件中的"加载目标"，然后等待板被加载。</li>
		<li>单击代表 MALDI 板的图像中的点，选择矩阵点的位置。</li>
		<li>在软件的"示例信息"选项卡中注明示例名称和文件夹。</li>
		<li>通过单击"收购"开始获取。</li>
		<li>在收购过程中，使用"MALDI 视频"选项卡上的鼠标指头稍微移动板，使激光点位于不同的点。</li>
		<li>收购完成后，转到"校准"选项卡，在二次模式下选择HCCA 校准列表，然后单击自动。全球校准结果在"校准图"窗口中表示，对于 SolariX XR 7T，应小于 0.2 ppm。</li>
		<li>如果校准良好，请单击"接受"并保存方法。</li>
	</ol>
</li>
	<li>样品上的基质沉积完成后，将幻灯片放在幻灯片适配器中，并使用塑料盖检索标记的位置。</li>
	<li>在灵活的图像软件中，使用打开软件的第一个窗口设置新的成像运行。<ol>
<li>命名成像运行，选择 结果目录，然后单击 "下一步"。</li>
		<li>指示鼠标大小（即用户定义的测量区域），选择要使用的方法（在第 3.1 节校准），然后单击 "下一步"。</li>
		<li>在扫描幻灯片并单击 "下一步"后，加载在第 1.6 步获得的幻灯片的光学图像。</li>
		<li>图像在更宽的窗口中打开。使用幻灯片上的标记来教导幻灯片的位置:在 ftmsControl中，将 MALDI 视频窗口的目标放在标记的确切位置上，然后返回 felx 图像 并单击光学图像上的完全相同的点。重复三个独立点。带有标记的塑料盖被放置在MALDI板上，以恢复其位置并便于教学。 注意:如果标记是用标记制作的，在幻灯片背面添加白色校正液可以使它们在教学过程中脱颖而出。</li>
	</ol>
</li>
	<li>使用"添加测量区域"工具在柔性图像软件中绘制样品感兴趣的区域。</li>
	<li>如果要分析几个样本，则保存成像运行和"自动序列"。</li>
	<li>如果分析多个样本，则使用"自动执行批次流体"启动序列。 注意:定期将数据同步到安全位置。</li>
</ol>4. 数据处理
<ol><li>将原始数据导入可视化软件 （SCILS 实验室），并创建数据集。此软件中分两个单独的步骤完成此操作。<ol>
<li>使用"批量导入器"工具并选择原始数据、指示目标目录并单击"导入"。</li>
		<li>导入后，可以组合多个数据集进行进一步分析。要组合数据集，请使用"文件|新|数据集"工具。</li>
		<li>选择用于获取的仪器类型，通过单击"+"添加导入数据集，并通过单击和拖动对象来排列图像。</li>
		<li>检查质量范围设置或在需要时通过指示兴趣范围进行修改。单击 "下一步 "查看导入摘要并启动导入。</li>
	</ol>
</li>
	<li>可视化样品和/或不同样品中不同组织中感兴趣的 m/z。 只需单击 光谱 即可选择感兴趣的 m/z 或在 m/z 框中键入值。<ol>
<li>如果需要，执行统计测试，以搜索不同组织和/或不同样本之间的共局部或歧视值，以确定感兴趣的 m/z。 这些工具在"工具"菜单中可用，不会在此协议中描述。</li>
	</ol>
</li>
	<li>从对象选项卡中导出感兴趣的m/z（例如，同地化、歧视性化合物）作为.csv文件。如果数据集不是太大（即最多 60，000 行），则也可以导出整个数据集。单击红色箭头指示的兴趣区域右侧的"出口"图标。</li>
	<li>导入.csv文件，以便在注释软件 （Metaboscape） 中创建新的数据集。点击"项目|导入CSV项目"。请注意，将只考虑确切的 m/z， 并且丢失了同位素配置文件。 注:5.0 软件版本允许从可视化软件直接导入数据，从而能够更准确地注释，因为可以考虑同位素配置文件。</li>
	<li>附有定制分析列表的注释，这些列表可以从公开的数据库中提取。软件会给出一个模板来创建分析列表。</li>
	<li>使用预测软件（代谢物预测）对注释化合物的代谢物进行硅基预测。需要开发利益复合物的公式，要么由软件中的用户绘制，要么导入为 .mol 文件。然后，该方法是一个简单的分步协议。</li>
	<li>恢复代谢物列表，创建分析列表，并在注释软件中使用它用预测代谢物注释原始数据。或者，如果代谢物列表很短，则手动按步骤 4.8 搜索。</li>
	<li>可视化软件中原始数据中代谢物的组织分布。</li>
	<li>通过右键单击预测的兴趣代谢物，恢复预测软件中代谢过程中所涉及的酶的名称。</li>
</ol>

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作者没有什么可透露的。

此协议的关键部分是样品准备:样品必须柔软且完好无损。切割是最困难的部分，因为样品的温度和厚度可能因所研究的样品类型而异。动物组织通常是同质的，更容易切割。植物样本通常包含不同的结构，因此由于刀片遇到软、硬或空血管组织，因此更难保持完好无损。强烈建议在与植物样本一起工作时使用新鲜组织，以避免在亲水组织中形成冰并破坏冰。切片存放在 ITO 涂层滑梯上时，必须轻?...

由于人类活动，异种生物在世界各地广泛分布。其中一些化合物是水溶性，并被土壤1吸收，并进入食物链时，他们积累在植物组织2，3，4。这些植物被昆虫和食草动物吃掉，它们是其他生物的猎物。一些异种生物的摄入及其对植物健康的影响被描述为5，6，7，8，但最近才在组织水平9。因此，目前还不清楚异种生物代谢发生于何处或如何发生，或者特定植物代谢物是否与特定组织中的异生物积累相关。此外，大多数研究忽视了植物中异种生物及其代谢物的新陈代谢，因此对植物组织中的这些反应知之甚少。
这里建议的是一种研究生物样本中的酶反应的方法，该反应可以与基质和反应产品的组织定位相关。该方法可以在一个实验中绘制生物样本的完整代谢剖面，因为分析是无针对性的，并且可以使用感兴趣的定制分析列表进行调查。提供的是在原始数据集中跟踪的候选人列表。如果在样本中注意到一个或几个感兴趣的分析，特定的组织定位可以提供有关相关生物过程的重要信息。然后，利用相关的生物定律在硅中修改感兴趣的分析，以寻找可能的产品/代谢物。然后，通过识别所涉及的酶并本地化组织中的反应来分析原始数据，从而帮助了解发生的代谢过程。没有其他方法提供生物样本中发生的反应类型、感兴趣化合物的本地化及其相关代谢物的信息。一旦有新鲜和完整的组织，并且感兴趣的化合物可以电解，这种方法可用于任何类型的生物材料。拟议的议定书发表在《维莱特》等12 期中，详见此处供科学界使用。

<table><tbody><tr><td>Cover slips</td><td>Bruker Daltonics</td><td>267942</td><td></td></tr><tr><td>Cryomicrotome</td><td>Thermo Scientific</td><td></td><td></td></tr><tr><td>Excel</td><td>Microsoft corporation</td><td></td><td></td></tr><tr><td>flexImaging</td><td>Bruker Daltonics</td><td></td><td></td></tr><tr><td>ftmsControl</td><td>Bruker Daltonics</td><td></td><td></td></tr><tr><td>GTX primescan</td><td>GX Microscopes</td><td></td><td></td></tr><tr><td>HCCA MALDI matrix</td><td>Bruker Daltonics</td><td>8201344</td><td></td></tr><tr><td>ImagePrep</td><td>Bruker Daltonics</td><td></td><td></td></tr><tr><td>ITO-coated slides</td><td>Bruker Daltonics</td><td>237001</td><td></td></tr><tr><td>M1-embedding matrix</td><td>ThermoScientific</td><td>1310</td><td></td></tr><tr><td>Metabolite Predict</td><td>Bruker Daltonics</td><td></td><td></td></tr><tr><td>Metaboscape</td><td>Bruker Daltonics</td><td></td><td></td></tr><tr><td>Methanol</td><td>Fisher Chemicals</td><td></td><td>No specific reference needed</td></tr><tr><td>MX 35 Ultra blades</td><td>Thermo Scientific</td><td>15835682</td><td></td></tr><tr><td>Plastic molds</td><td></td><td></td><td>No specific reference needed</td></tr><tr><td>SCiLS Lab</td><td>Bruker Daltonics</td><td></td><td></td></tr><tr><td>SolariX XR 7Tesla</td><td>Bruker Daltonics</td><td></td><td>The method proposed is not limited to this instrument</td></tr><tr><td>Spray sheets for ImagePrep</td><td>Bruker Daltonics</td><td>8261614</td><td></td></tr><tr><td>TFA</td><td>Sigma Aldrich</td><td></td><td>No specific reference needed</td></tr></tbody></table>

investigation of xenobiotics metabolism in salix alba leaves via mass spectrometry imaging

所介绍的方法使用质谱成像（MSI）来建立 S.阿尔巴 叶在接触异种生物时的代谢轮廓。使用非靶向方法，在植物组织中识别和本地化感兴趣的植物代谢物和异种生物，以发现特定的分布模式。然后，在从已识别的异种生物中预测潜在的代谢物（即代谢物和结合物）。当异生物代谢物位于组织中时，记录植物改变其所涉及的酶类型。这些结果用于描述在 S.alba 叶中发生的不同类型的生物反应，以回应叶子中的异生物积累。代谢物在两代人中预测，允许记录连续的生物反应，以改变叶组织中的异种生物。

此协议适用于从暴露于环境中的异种生物的S. alba树中采样的新鲜叶子。这个过程在图1中描述。第一步是准备兴趣样本的薄片。植物样本通常比动物样本更难切割，因为组织是异质的，可以含有水和/或空气。此困难使用嵌入介质处理，在样品周围形成均匀块。矩阵沉积通过使用机器人，避免手部操纵和确保可重复的结果而得到促进。MALDI基质层厚度在整个过程中遵循?...

Watch this Scientific Journal Video about Investigation of Xenobiotics Metabolism In Salix alba Leaves via Mass Spectrometry Imaging at JoVE.com

Investigation of Xenobiotics Metabolism In Salix alba Leaves via Mass Spectrometry Imaging

这种方法使用质谱成像（MSI）来了解在接触异种生物时 ，S.阿尔巴 叶的代谢过程。该方法允许在特定、完整的组织内对感兴趣的化合物及其预测的代谢物进行空间定位。

通过质谱成像对 萨利克斯阿尔巴 叶中异种生物代谢的调查

The method presented uses mass spectrometry imaging (MSI) to establish the metabolic profile of S. alba leaves when exposed to xenobiotics. Using a ...

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Research

JoVE Journal

Environment

Investigation of Xenobiotics Metabolism In Salix alba Leaves via Mass Spectrometry Imaging

3.0K 次观看.  Université de Strasbourg. 这种方法使用质谱成像（MSI）来了解在接触异种生物时 ，S.阿尔巴 叶的代谢过程。该方法允许在特定、完整的组织内对感兴趣的化合物及其预测的代谢物进行空间定位。

视频: Investigation of Xenobiotics Metabolism In Salix alba Leaves via Mass Spectrometry Imaging

Untargeted Metabolomics from Biological Sources Using Ultraperformance Liquid Chromatography-High Resolution Mass Spectrometry (UPLC-HRMS)

Here we present a workflow to analyze the metabolic profiles for biological samples of interest including; cells, serum, or tissue. The sample is first separated into polar and non-polar fractions by a liquid-liquid phase extraction, and partially purified to facilitate downstream analysis. Both aqueous (polar metabolites) and organic (non-polar metabolites) phases of the initial extraction are processed to survey a broad range of metabolites. Metabolites are separated by different liquid chromatography methods based upon their partition properties. In this method, we present microflow ultra-performance (UP)LC methods, but the protocol is scalable to higher flows and lower pressures. Introduction into the mass spectrometer can be through either general or compound optimized source conditions. Detection of a broad range of ions is carried out in full scan mode in both positive and negative mode over a broad m/z range using high resolution on a recently calibrated instrument. Label-free differential analysis is carried out on bioinformatics platforms. Applications of this approach include metabolic pathway screening, biomarker discovery, and drug development.

Untargeted Metabolomics from Biological Sources Using Ultraperformance Liquid Chromatography-High Resolution Mass Spectrometry UPLC-HRMS

Untargeted metabolomics provides a hypothesis generating snapshot of a metabolic profile. This protocol will demonstrate the extraction and analysis of metabolites from cells, serum, or tissue. A range of metabolites are surveyed using liquid-liquid phase extraction, microflow ultraperformance liquid chromatography/high-resolution mass spectrometry (UPLC-HRMS) coupled to differential analysis software.

不相关的代谢组学，生物源使用超高效液相色谱 - 高分辨质谱（UPLC-HRMS）

Here we present a workflow to analyze the metabolic profiles for biological samples of interest including; cells, serum, or tissue. The sample is first ...

科研

化学

Transcript and Metabolite Profiling for the Evaluation of Tobacco Tree and Poplar as Feedstock for the Bio-based Industry

The global demand for food, feed, energy, and water poses extraordinary challenges for future generations. It is evident that robust platforms for the exploration of renewable resources are necessary to overcome these challenges. Within the multinational framework MultiBioPro we are developing biorefinery pipelines to maximize the use of plant biomass. More specifically, we use poplar and tobacco tree (Nicotiana glauca) as target crop species for improving saccharification, isoprenoid, long chain hydrocarbon contents, fiber quality, and suberin and lignin contents. The methods used to obtain these outputs include GC-MS, LC-MS and RNA sequencing platforms. The metabolite pipelines are well established tools to generate these types of data, but also have the limitations in that only well characterized metabolites can be used. The deep sequencing will allow us to include all transcripts present during the developmental stages of the tobacco tree leaf, but has to be mapped back to the sequence of Nicotiana tabacum. With these set-ups, we aim at a basic understanding for underlying processes and at establishing an industrial framework to exploit the outcomes. In a more long term perspective, we believe that data generated here will provide means for a sustainable biorefinery process using poplar and tobacco tree as raw material. To date the basal level of metabolites in the samples have been analyzed and the protocols utilized are provided in this article.

Plant biomass offers a renewable resource for multiple products, including fuel, feed, food, and a variety of materials. In this paper we investigate the properties of tobacco tree (Nicotiana glauca) and poplar as suitable sources for a biorefinery pipeline.

成绩单及代谢物谱烟草树和杨树的评价作为原料的生物基工业

The global demand for food, feed, energy, and water poses extraordinary challenges for future generations. It is evident that robust platforms for the ...

环境科学

Measuring Rates of Herbicide Metabolism in Dicot Weeds with an Excised Leaf Assay

In order to isolate and accurately determine rates of herbicide metabolism in an obligate-outcrossing dicot weed, waterhemp (Amaranthus tuberculatus), we developed an excised leaf assay combined with a vegetative cloning strategy to normalize herbicide uptake and remove translocation as contributing factors in herbicide-resistant (R) and &#8211;sensitive (S) waterhemp populations. Biokinetic analyses of organic pesticides in plants typically include the determination of uptake, translocation (delivery to the target site), metabolic fate, and interactions with the target site. Herbicide metabolism is an important parameter to measure in herbicide-resistant weeds and herbicide-tolerant crops, and is typically accomplished with whole-plant tests using radiolabeled herbicides. However, one difficulty with interpreting biokinetic parameters derived from whole-plant methods is that translocation is often affected by rates of herbicide metabolism, since polar metabolites are usually not mobile within the plant following herbicide detoxification reactions. Advantages of the protocol described in this manuscript include reproducible, accurate, and rapid determination of herbicide degradation rates in R and S populations, a substantial decrease in the amount of radiolabeled herbicide consumed, a large reduction in radiolabeled plant materials requiring further handling and disposal, and the ability to perform radiolabeled herbicide experiments in the lab or growth chamber instead of a greenhouse. As herbicide resistance continues to develop and spread in dicot weed populations worldwide, the excised leaf assay method developed and described herein will provide an invaluable technique for investigating non-target site-based resistance due to enhanced rates of herbicide metabolism and detoxification.

This manuscript describes how herbicide metabolism rates can be effectively quantified with excised leaves from a dicot weed, thereby reducing variability and removing any possible confounding effects of herbicide uptake or translocation typically observed in whole-plant assays.

测量除草剂代谢的双子叶杂草价格与切下的叶片分析

In order to isolate and accurately determine rates of herbicide metabolism in an obligate-outcrossing dicot weed, waterhemp (Amaranthus tuberculatus), we ...

Leaf Spray Mass Spectrometry: A Rapid Ambient Ionization Technique to Directly Assess Metabolites from Plant Tissues

Plants produce thousands of small molecules that are diverse in their chemical properties. Mass spectrometry (MS) is a powerful technique for analyzing plant metabolites because it provides molecular weights with high sensitivity and specificity. Leaf spray MS is an ambient ionization technique where plant tissue is used for direct chemical analysis via electrospray, eliminating chromatography from the process. This approach to sampling metabolites allows for a wide range of chemical classes to be detected simultaneously from intact plant tissues, minimizing the amount of sample preparation needed. When used with a high-resolution, accurate mass MS, leaf spray MS facilitates the rapid detection of metabolites of interest. It is also possible to collect tandem mass fragmentation data with this technique to facilitate a compound identification. The combination of accurate mass measurements and fragmentation is beneficial in confirming compound identities. The leaf spray MS technique requires only minor modifications to a nanospray ionization source and is a useful tool to further expand the capabilities of a mass spectrometer. Here, fresh leaf tissue from Sceletium tortuosum (Aizoaceae), a traditional medicinal plant from South Africa, is analyzed; numerous mesembrine alkaloids are detected with leaf spray MS.

Leaf spray mass spectrometry is a direct chemical analysis technique that minimizes the sample preparation and eliminates chromatography, allowing for the rapid detection of small molecules from plant tissues.

叶喷雾质谱: 一种快速的环境电离技术直接评价植物组织中的代谢产物

Plants produce thousands of small molecules that are diverse in their chemical properties. Mass spectrometry (MS) is a powerful technique for analyzing ...

生物化学

Elucidating the Metabolism of 2,4-Dibromophenol in Plants

Crops can be extensively exposed to organic pollutants, since soil is a major sink for pollutants discarded into the environment. This creates potential human exposure through the consumption of pollutant-accumulated foods. Elucidating the uptake and metabolism of xenobiotics in crops is essential for the assessment of dietary exposure risk in humans. However, for such experiments, the use of intact plants requires long-term experiments and complex sample preparation protocols that can be affected by various factors. Plant callus cultures combined with high-resolution mass spectrometry (HRMS) may provide a solution for the accurate and time-saving identification of metabolites of xenobiotics in plants, as it can avoid interference from the microbial or fungal microenvironment, shorten the treatment duration, and simplify the matrix effect of intact plants. 2,4-dibromophenol, a typical flame retardant and endocrine disrupter, was chosen as the model substance due to its widespread occurrence in soil and its uptake potential by plants. Herein, plant callus was generated from asepsis seeds and exposed to sterile 2,4-dibromophenol-containing culture medium. The results showed that eight metabolites of 2,4-dibromophenol were identified in the plant callus tissues after 120 h of incubation. This indicates that 2,4-dibromophenol was rapidly metabolized in&#160;the plant callus tissues. Thus, the plant callus culture platform is an effective method to evaluate the uptake and metabolism of xenobiotics in plants.

The present protocol describes a simple and efficient method for the identification of 2,4-dibromophenol metabolites in plants.

阐明植物中2,4-二溴苯酚的代谢

Crops can be extensively exposed to organic pollutants, since soil is a major sink for pollutants discarded into the environment. This creates potential ...

Semi-Targeted Ultra-High-Performance Chromatography Coupled to Mass Spectrometry Analysis of Phenolic Metabolites in Plasma of Elderly Adults

A group of 23 elderly persons was given functional meals (a beverage and a muffin) specially formulated for the prevention of sarcopenia (age-related loss of muscle mass). Plasma samples were taken at the beginning of the intervention and after 30 days of consuming the functional meals. A semi-targeted ultra-high-performance chromatography coupled with tandem mass (UPLC-MS/MS) analysis was carried out to identify phenolic compounds and their metabolites. Plasma proteins were precipitated with ethanol and the samples were concentrated and resuspended in the mobile phase (1:1 acetonitrile: water) before injection into the UPLC-MS/MS instrument. Separation was carried out with a C18 reverse-phase column, and compounds were identified using their experimental mass, isotopic distribution, and fragment pattern. Compounds of interest were compared to those of data banks and the internal semi-targeted library. Preliminary results showed that the major metabolites identified after the intervention were phenylacetic acid, glycitin, 3-hydroxyphenylvaleric acid, and gomisin M2.

The goal of this protocol is to detect phenolic metabolites in plasma using a semi-targeted chromatography-mass spectrometry method.

老年人血浆中酚类代谢物的半靶向超高效色谱耦合质谱分析

A group of 23 elderly persons was given functional meals (a beverage and a muffin) specially formulated for the prevention of sarcopenia (age-related loss ...

Atmospheric-pressure Molecular Imaging of Biological Tissues and Biofilms by LAESI Mass Spectrometry

Ambient ionization methods in mass spectrometry allow analytical investigations to be performed directly on a tissue or biofilm under native-like experimental conditions. Laser ablation electrospray ionization (LAESI) is one such development and is particularly well-suited for the investigation of water-containing specimens. LAESI utilizes a mid-infrared laser beam (2.94 &mu;m wavelength) to excite the water molecules of the sample. When the ablation fluence threshold is exceeded, the sample material is expelled in the form of particulate matter and these projectiles travel to tens of millimeters above the sample surface. In LAESI, this ablation plume is intercepted by highly charged droplets to capture a fraction of the ejected sample material and convert its chemical constituents into gas-phase ions. A mass spectrometer equipped with an atmospheric-pressure ion source interface is employed to analyze and record the composition of the released ions originating from the probed area (pixel) of the sample. A systematic interrogation over an array of pixels opens a way for molecular imaging in the microprobe analysis mode. A unique aspect of LAESI mass spectrometric imaging is depth profiling that, in combination with lateral imaging, enables three-dimensional (3D) molecular imaging. With current lateral and depth resolutions of ~100 &mu;m and ~40 &mu;m, respectively, LAESI mass spectrometric imaging helps to explore the molecular structure of biological tissues. Herein, we review the major elements of a LAESI system and provide guidelines for a successful imaging experiment.

Laser ablation electrospray ionization (LAESI) is an atmospheric-pressure ion source for mass spectrometry. In the imaging mode, a mid-infrared laser probes the distributions of molecules across a tissue section or a biofilm. This technique presents a new approach for diverse bioanalytical studies carried out under native experimental conditions.

常压LAESI质谱生物组织和生物膜的分子成像

Ambient ionization methods in mass spectrometry allow analytical investigations to be performed directly on a tissue or biofilm under native-like ...

生物学

<meta charset="utf8"></head><body>通过 UPLC-TOF 质谱法鉴定 双色 Gynura bicolor 的化学成分

High-resolution Tandem Mass Spectrometry for Studying Chemical Constituents of Gynura bicolor DC

The separation and analysis of the desired chemical components are important subjects for the fundamental research of traditional Chinese medicine (TCM). Ultra-high-performance liquid chromatography quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS/MS) has gradually become a leading technology for the identification of TCM ingredients. Gynura bicolor DC. (BFH), a perennial stemless herb used for medicine and food in China has medicinal effects such as clearing heat, moistening the lung, relieving cough, dispersing stasis, and relieving swelling. Polyphenols and flavonoids contain numerous isomers, which hinder the identification of the complex compounds in BFH. This paper presents a systematic protocol for studying chemical constituents of BFH based on solvent extraction and integrated data via UPLC-Q-TOF-MS.
The method described here includes systematic protocols for sample pretreatment, MS calibration, MS acquisition, data processing, and analysis of results. Sample pretreatment includes collection, cleaning, drying, crushing, and extraction. MS calibration consists of multipoint and single-point correction. Data processing includes data importing, method establishment, analysis processing, and result presentation. Representative results of the typical fragmentation pattern of phenolic acids, esters, and glycosides in Gynura bicolor DC. (BFH) are presented in this paper. In addition, organic solvent selection, extraction, data integration, collision energy selection, and method improvement are discussed in detail. This universal protocol can be widely used to identify complex compounds in TCM.

<meta charset="utf8"></head><body>用于高分辨率串联质谱分析的 Gynura bicolor DC 样品的制备

We describe a general protocol that integrates high-resolution mass spectrometry analysis and molecular docking in traditional Chinese medicine research.

用于研究双色 DC 化学成分的高分辨率串联质谱法

The separation and analysis of the desired chemical components are important subjects for the fundamental research of traditional Chinese medicine (TCM). ...

通过质谱成像对萨利克斯阿尔巴叶中异种生物代谢的调查

摘要

探索更多视频

此视频中的章节

不相关的代谢组学，生物源使用超高效液相色谱 - 高分辨质谱（UPLC-HRMS）

成绩单及代谢物谱烟草树和杨树的评价作为原料的生物基工业

测量除草剂代谢的双子叶杂草价格与切下的叶片分析

叶喷雾质谱: 一种快速的环境电离技术直接评价植物组织中的代谢产物

阐明植物中2,4-二溴苯酚的代谢

老年人血浆中酚类代谢物的半靶向超高效色谱耦合质谱分析

常压LAESI质谱生物组织和生物膜的分子成像

用于研究双色 DC 化学成分的高分辨率串联质谱法

用于研究双色 DC 化学成分的高分辨率串联质谱法

用于研究双色 DC 化学成分的高分辨率串联质谱法

通过质谱成像对 萨利克斯阿尔巴 叶中异种生物代谢的调查

摘要

探索更多视频

此视频中的章节

不相关的代谢组学，生物源使用超高效液相色谱 - 高分辨质谱（UPLC-HRMS）

成绩单及代谢物谱烟草树和杨树的评价作为原料的生物基工业

测量除草剂代谢的双子叶杂草价格与切下的叶片分析

叶喷雾质谱: 一种快速的环境电离技术直接评价植物组织中的代谢产物

阐明植物中2,4-二溴苯酚的代谢

老年人血浆中酚类代谢物的半靶向超高效色谱耦合质谱分析

常压LAESI质谱生物组织和生物膜的分子成像

用于研究双色 DC 化学成分的高分辨率串联质谱法

用于研究双色 DC 化学成分的高分辨率串联质谱法

用于研究双色 DC 化学成分的高分辨率串联质谱法

通过质谱成像对萨利克斯阿尔巴叶中异种生物代谢的调查