Name: in situ characterization of shewanella oneidensis mr1 biofilms by salvi and tof-sims
Uploaded: 2017-08-18T13:00:00.000+00:00
Duration: 9 min 56 s
Description: Watch this Scientific Journal Video about In Situ Characterization of Shewanella oneidensis MR1 Biofilms by SALVI and ToF-SIMS at JoVE.com

我们非常感谢太平洋西北国家实验室 （单比） 地球和生物科学 (EBD) 特派团种子实验室指导研究与发展 (LDRD) 基金的支持。通过 W.R.威利环境分子科学实验室 （其） 一般用户建议提供了工具的访问。其是由办公室生物和环境研究 (BER) 在太平洋西北国家实验室主办全国科学用户设施。作者感谢丁博士曌校对手稿和提供有用的反馈。太平洋西北国家实验室是美国能源部下合同 DE-AC05-76RL01830 由巴特尔推行。

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作者没有透露。

后接种日志阶段，它是重要测试数天和在其中生物膜应成长之前它是健康和成像，够厚在第 3.1 步中所述的温度。此过程具体包括培养 S.oneidensis MR1 生物膜在室温;然而不同的室内温度可以影响率的增长。因此，使用光学成像来了解生物膜是否已准备好之前 TOF-SIMS 分析至关重要。同样，不同株细菌需要不同生长条件和长度来实现理想的厚度进行分析。图 1b 中的生长曲线描绘了这种细菌要 12-32 h 第 2...

细菌生物被膜表面相关社区给细菌提供生存变不利的物理和机械刺激，其中细胞都能够重视，并在许多可能的环境中生存的防御随着时间推移逐渐形成了。1,2生物膜大大调查和在生物医学、 生物医学工程、 农业和工业研究和发展等很多领域有应用。1,2理解这些复杂的微生物群落，包括他们自身产生的胞外聚合物 (EPS) 和他们的当地水-群集环境中，化学图谱至关重要获得准确和详细其生物活动的描述。2
生物膜存在，但在高度水化状态的成长。这带来一个巨大的挑战，在使用基于真空的表面分析技术，如飞行时间二次离子质谱 (TOF-SIMS) 由于研究挥发性液体在真空中的困难。因此，基于真空的表面分析技术已几乎完全限于研究生物膜的样本，只是他们干的状态。然而，研究其干州生物膜抑制准确调查其真实的生物微环境。它常常引起 EPS 完整性和生物膜形态，比较干膜质谱结果到原位液体研究后证明了剧变。3,4这篇文章提出了一个解决方案利用我们的系统用于分析在液体真空接口 （萨尔），5，6微流控反应器研究生物膜内他们自然的水合状态，包含在其薄硅氮化 (SiN) 膜在微通道的聚二甲基硅氧烷 （精原细胞瘤），从而同时仍保持在真空内的液体矩阵的结构完整性提供直接访问二次离子探针光束下的液态分庭。7,8
S.oneidensis先生-1 突变表达绿色荧光蛋白 (GFP) 被选为模式生物的由于其代谢的多功能性和共同使用的环境和应用微生物学，基于此生物膜过程图很大程度上金属还原和胞外电子转移的独特能力。9,10,11此外，绿色荧光蛋白的存在允许容易连续生物膜-厚度监测通过荧光显微镜、 荧光素异硫氰酸酯 (FITC) 筛选器使用。我们以往的研究表明倾向于使用在原位荧光成像技术对生物膜的生长厚度达 100 微米的罪窗口的附件此细菌的证据。4,12虽然本文将只讨论通过荧光显微镜观察生物被膜的存在的确认，萨尔维是兼容其他光学超分辨成像方法荧光成像 （即结构照明显微镜 (SIM)9) 和共焦激光扫描显微镜 (CLSM) 成像4)。光学成像可以作为衡量生物膜厚度，并获取三维图像的生物膜的形状看来，确认其厚度和其附件罪窗口。9虽然 GFP 用于 SIMS 分析， S.oneidensis没有绿色荧光蛋白用作这唯一所需测量的光学密度的生长曲线，并不需要作任何荧光成像。一般来说的区别 GFP 标记和未加标签的造林树种生长曲线是微不足道。此外，虽然本议定书使用美国 oneidensis先生 1 GFP 作为模式生物来描述过程，此过程旨在为任何可能需要在萨尔内培养的细菌菌株。虽然鉴于菌株所需的知识，一些生长条件，如时间、 温度和氧气环境可能需要修改，以适应的菌株，用于。对于生长介质，此过程使用"纳米"中等、 胰酪胨大豆肉汤 (TSB) 葡萄糖，而胰酪胨大豆琼脂 (TSA) 葡萄糖不培养。"纳米"培养基的组成已专门制定了为增长和监测膜扩展和美国 oneidensis出现初具规模的小电线及培养基成分质已在以往的研究内设立。13,14
我们以前的协议，在原位上液体 TOF-SIMS 阐释了萨尔维已为蛋白质固定化和罪恶，以及 TOF-SIMS 分析和数据减少详细的议定书的附件提供的好处。12 ，而不是重申数据减少步骤，本文将有助于集中精力建立和培养生物膜内我们萨尔维微通道，以及成像的步骤来检测生物膜的存在和厚度事先的独特方法TOF-SIMS 分析。而生物膜有以前仅限于只干燥样品内室基于真空的表面分析技术，详细的 EPS 和生物膜化学映射的活生物膜现在可原位由于这一新功能。

<table><tbody><tr><td>ToF-SIMS</td><td>IONTOF</td><td>TOF.SIMS 5</td><td>Resolution:&gt;10,000 m/&amp;Delta;m for mass resolution;&gt;4,000 m/&amp;Delta;m for high spatial resolution</td></tr><tr><td>System for Analysis at the Liquid Vacuum Interface (SALVI)</td><td>Pacific Northwest National Laboratory</td><td>N/A</td><td>SALVI is a unique, self-contained, portable analytical tool that, for the first time, enables vacuum based scientific instruments such as time-of-flight secondary ion mass spectrometry (ToF-SIMS) to analyze liquid surfaces in their natural state at the molecular level.</td></tr><tr><td>-80&amp;deg;C Freezer</td><td>New Brunswick Scientific</td><td>N/A</td><td>U410 Premium Energy Efficient Ultra-Low Temperature Freezer</td></tr><tr><td>4&amp;deg;C Refrigerator</td><td>BioCold Scientific</td><td>N/A</td><td>COLDBOX1</td></tr><tr><td>Orbital Shaker</td><td>New Brunswick Scientific</td><td>N/A</td><td>Innova 4900 Multi-Tier Environmental Shaker, set at 30 degrees Celsius for serum bottle and flask culturing, set at 150rpm.</td></tr><tr><td>Syringe Pump</td><td>Cole-Parmer</td><td>EW-74905-02</td><td>Cole-Parmer Syringe Pump, Infusion Only, Touchscreen Control 74905-02, used for injecting liquid into the tubing system and SALVI at a constant flowrate.</td></tr><tr><td>Incubator</td><td>Barnstead International</td><td>LT1465X3</td><td>Lab-Line incubator, set at 30 degrees Celsius for plate culturing.</td></tr><tr><td>Autoclave</td><td>Getinge</td><td>533LS</td><td>Used to sterilize PEEK fittings, tubing systems, serum vials, and medium. Model 533LS Vacuum Steam Sterilizer</td></tr><tr><td>Spectrophotometer</td><td>Thermo Fisher Scientific</td><td>4001-000</td><td>GENESYS 20 spectrophotometer for OD600 readings of cuvettes for growth curves.</td></tr><tr><td>Biological Safety Cabinet</td><td>Thermo Fisher Scientific</td><td>1385</td><td>1300 Series AZ Biological Safety Cabinet</td></tr><tr><td>Fluorescence Microscope</td><td>Nikon</td><td>N/A</td><td>Nikon OPTIPHOT-2 fluorescence microscope with camera and super high pressure mercury lamp power supply.</td></tr><tr><td>pH Meter</td><td>Mettler Toledo</td><td>51302803</td><td>Used to test the pH of the &amp;ldquo;nanowires&amp;rdquo; medium after finished and before autoclaving.</td></tr><tr><td>PEEK Union</td><td>Valco</td><td>ZU1TPK</td><td>For connecting the inlet and outlet of SALVI, the syringe to the tubing system, and the inlet of the SALVI to the drip chamber of the tubing system.</td></tr><tr><td>5 Axes Sample Stage</td><td>IONTOF</td><td>N/A</td><td>Stage is self-made for mounting SALVI in ToF-SIMS.</td></tr><tr><td>Barnstead Nanopure Water Purification System</td><td>Thermo Fisher Scientific</td><td>D11921</td><td>ROpure LP Reverse Osmosis filtration module (D2716)</td></tr><tr><td>Pipette</td><td>Thermo Fisher Scientific</td><td>21-377-821</td><td>Range: 100 to 1,000 &amp;micro;L.</td></tr><tr><td>Pipette Tip</td><td>Neptune</td><td>2112.96.BS</td><td>1,000 &amp;micro;L pipette tips</td></tr><tr><td>Razor Blade Handle</td><td>Stanley</td><td>N/A</td><td>Stanley Bostitch Razor Blade Scraper with 5 Single-Edge Blades, used for cutting PTFE tubing</td></tr><tr><td>Syringe</td><td>BD</td><td>309659</td><td>1 mL</td></tr><tr><td>Syringe</td><td>BD</td><td>309657</td><td>3 mL</td></tr><tr><td>Syringe</td><td>BD</td><td>309646</td><td>5 mL; Used for making the drip chamber</td></tr><tr><td>Syringe</td><td>BD</td><td>309604</td><td>10 mL</td></tr><tr><td>Syringe</td><td>BD</td><td>302830</td><td>20 mL</td></tr><tr><td>Disposable Pipette</td><td>Thermo Fisher Scientific</td><td>13-678-11</td><td>25 mL Fisherbrand&amp;trade; Sterile Polystyrene Disposable Serological Pipets with Magnifier Stripe, for filling serum bottles.</td></tr><tr><td>Electric Pipette Filler</td><td>Pipet-aid</td><td>P-57260</td><td>Vacuum pressure electric serological pipette filler</td></tr><tr><td>Serum Bottle</td><td>Sigma</td><td>33109-U</td><td>Holds approximately 69 mL of liquid for culture growth, optimum for use of 20mL culture per bottle.</td></tr><tr><td>Anaerobic Culture Tube</td><td>VWR</td><td>89167-178</td><td>Anaerobic Tubes, 18 x 150 mm, Supplied with 20 mm Blue Butyl Rubber Stopper and Aluminum Seal.</td></tr><tr><td>Rubber Stopper</td><td>Sigma</td><td>27235-U</td><td>Silicone stopper, used for sealing serum bottles and for creating the tubing system/drip chamber.</td></tr><tr><td>Aluminum Crimp Seal (without septum)</td><td>Sigma</td><td>27227-U</td><td>Aluminum seal for top of serum bottle for use with serum bottle crimper.</td></tr><tr><td>Serum Bottle Aluminum Seal Crimper</td><td>Wheaton</td><td>224307</td><td>30 mm crimper with standard seal.</td></tr><tr><td>PTFE Tubing</td><td>Supelco</td><td>58697-U</td><td>1.58 mm OD x 0.5 mm ID 50 ft. PTFE Teflon tubing, used for creating the tubing system.</td></tr><tr><td>Disposable Cuvettes</td><td>GMBH</td><td>759085D</td><td>1.5 Ml for use with spectrophotometer.</td></tr><tr><td>Needle</td><td>BD</td><td>303015</td><td>22G; used for serum bottle injection.</td></tr><tr><td>Needle</td><td>BD</td><td>305120</td><td>23G; used for punching-through rubber stopper to create drip tubing system.</td></tr><tr><td>Shewanella oneidensis MR-1 with GFP</td><td>N/A</td><td>N/A</td><td>Matthysse AG, Stretton S, Dandie C, McClure NC, &amp;amp; Goodman AE (1996) Construction of GFP vectors for use in Gram-negative bacteria other than Escherichia coli. FEMS Microbiol Lett 145(1):87-94.&amp;nbsp;</td></tr><tr><td>Ethanol</td><td>Thermo Fisher Scientific</td><td>&amp;nbsp;S25310A</td><td>95% Denatured</td></tr><tr><td>TSA</td><td>BD</td><td>212305</td><td>Tryptic soy agar for culturing the model organism (S. oneidensis) used in this protocol</td></tr><tr><td>PIPES Buffer</td><td>Sigma</td><td>P-1851</td><td>Used for &amp;ldquo;nanowires&amp;rdquo; medium {Hill, E.A. 2007}</td></tr><tr><td>Sodium Hydroxide</td><td>Sigma</td><td>S-5881</td><td>Used for &amp;ldquo;nanowires&amp;rdquo; medium {Hill, E.A. 2007}</td></tr><tr><td>Ammonium Chloride</td><td>Sigma</td><td>A-5666</td><td>Used for &amp;ldquo;nanowires&amp;rdquo; medium {Hill, E.A. 2007}</td></tr><tr><td>Potassium Chloride</td><td>Sigma</td><td>P-4504</td><td>Used for &amp;ldquo;nanowires&amp;rdquo; medium {Hill, E.A. 2007}</td></tr><tr><td>Sodium Phosphate Monobasic</td><td>Sigma</td><td>S-9638</td><td>Used for &amp;ldquo;nanowires&amp;rdquo; medium {Hill, E.A. 2007}</td></tr><tr><td>Sodium Chloride</td><td>Thermo Fisher Scientific</td><td>S271-3</td><td>Used for &amp;ldquo;nanowires&amp;rdquo; medium, and used to make mineral solution used for &amp;ldquo;nanowires&amp;rdquo; medium {Hill, E.A. 2007}</td></tr><tr><td>Sodium lactate</td><td>Sigma</td><td>L-1375</td><td>60%(w/w) syrup @ 98% pure, d=1.3 g/mL, 7M, used for &amp;ldquo;nanowires&amp;rdquo; medium {Hill, E.A. 2007}</td></tr><tr><td>Sodium Bicarbonate</td><td>Sigma</td><td>S-5761</td><td>Used to make ferric NTA solution, used for &amp;ldquo;nanowires&amp;rdquo; medium {Hill, E.A. 2007}</td></tr><tr><td>Nitrilotriacetic Acid Trisodium Salt</td><td>Sigma</td><td>N-0253</td><td>Used to make ferric NTA solution, used for &amp;ldquo;nanowires&amp;rdquo; medium {Hill, E.A. 2007}</td></tr><tr><td>Iron (III) Chloride</td><td>Sigma</td><td>451649</td><td>Used to make ferric NTA solution, used for &amp;ldquo;nanowires&amp;rdquo; medium {Hill, E.A. 2007}</td></tr><tr><td>Magnesium Sulfate</td><td>Sigma</td><td>208094</td><td>Used to make minerals solution, used for &amp;ldquo;nanowires&amp;rdquo; medium {Hill, E.A. 2007}</td></tr><tr><td>Manganese (II) Sulfate Monohydrate</td><td>Sigma</td><td>M-7634</td><td>Used to make minerals solution, used for &amp;ldquo;nanowires&amp;rdquo; medium {Hill, E.A. 2007}</td></tr><tr><td>Iron(II) Sulfate Heptahydrate</td><td>Sigma</td><td>215422</td><td>Used to make minerals solution, used for &amp;ldquo;nanowires&amp;rdquo; medium {Hill, E.A. 2007}</td></tr><tr><td>Calcium Chloride Dihydrate</td><td>Sigma</td><td>223506</td><td>Used to make minerals solution, used for &amp;ldquo;nanowires&amp;rdquo; medium {Hill, E.A. 2007}</td></tr><tr><td>Cobalt(II) Chloride</td><td>Sigma</td><td>60818</td><td>Used to make minerals solution, used for &amp;ldquo;nanowires&amp;rdquo; medium {Hill, E.A. 2007}</td></tr><tr><td>Zinc Chloride</td><td>Sigma</td><td>229997</td><td>Used to make minerals solution, used for &amp;ldquo;nanowires&amp;rdquo; medium {Hill, E.A. 2007}</td></tr><tr><td>Copper(II) Sulfate Pentahydrate</td><td>Sigma</td><td>C-8027</td><td>Used to make minerals solution, used for &amp;ldquo;nanowires&amp;rdquo; medium {Hill, E.A. 2007}</td></tr><tr><td>Aluminum Potassium Sulfate Dodecahydrate</td><td>Sigma</td><td>237086</td><td>Used to make minerals solution, used for &amp;ldquo;nanowires&amp;rdquo; medium {Hill, E.A. 2007}</td></tr><tr><td>Boric Acid</td><td>Sigma</td><td>B-6768</td><td>Used to make minerals solution, used for &amp;ldquo;nanowires&amp;rdquo; medium {Hill, E.A. 2007}</td></tr><tr><td>Sodium Molybdate Dihydrate</td><td>Sigma</td><td>331058</td><td>Used to make minerals solution, used for &amp;ldquo;nanowires&amp;rdquo; medium {Hill, E.A. 2007}</td></tr><tr><td>Nickel(II) Chloride</td><td>Sigma</td><td>339350</td><td>Used to make minerals solution, used for &amp;ldquo;nanowires&amp;rdquo; medium {Hill, E.A. 2007}</td></tr><tr><td>Sodium Tungstate Dihydrate</td><td>Sigma</td><td>14304</td><td>Used to make minerals solution, used for &amp;ldquo;nanowires&amp;rdquo; medium {Hill, E.A. 2007}</td></tr><tr><td>D-Biotin</td><td>Sigma</td><td>47868</td><td>Used to make vitamin solution, used for &amp;ldquo;nanowires&amp;rdquo; medium {Hill, E.A. 2007}</td></tr><tr><td>Folic Acid</td><td>Sigma</td><td>F-7876</td><td>Used to make vitamin solution, used for &amp;ldquo;nanowires&amp;rdquo; medium {Hill, E.A. 2007}</td></tr><tr><td>Pyridoxine Hydrochloride</td><td>Sigma</td><td>P-9755</td><td>Used to make vitamin solution, used for &amp;ldquo;nanowires&amp;rdquo; medium {Hill, E.A. 2007}</td></tr><tr><td>Riboflavin (B2)</td><td>Sigma</td><td>47861</td><td>Used to make vitamin solution, used for &amp;ldquo;nanowires&amp;rdquo; medium {Hill, E.A. 2007}</td></tr><tr><td>Thiamine Hydrochloride</td><td>Sigma</td><td>T-4625</td><td>Used to make vitamin solution, used for &amp;ldquo;nanowires&amp;rdquo; medium {Hill, E.A. 2007}</td></tr><tr><td>Nicotinic Acid</td><td>Sigma</td><td>N4126</td><td>Used to make vitamin solution, used for &amp;ldquo;nanowires&amp;rdquo; medium {Hill, E.A. 2007}</td></tr><tr><td>D-Pantothenic Acid Hemicalcium Salt</td><td>Sigma</td><td>21210</td><td>Used to make vitamin solution, used for &amp;ldquo;nanowires&amp;rdquo; medium {Hill, E.A. 2007}</td></tr><tr><td>Vitamin B12</td><td>Sigma</td><td>V-2876</td><td>Used to make vitamin solution, used for &amp;ldquo;nanowires&amp;rdquo; medium {Hill, E.A. 2007}</td></tr><tr><td>4-Aminobenzoic Acid</td><td>Sigma</td><td>A-9878</td><td>Used to make vitamin solution, used for &amp;ldquo;nanowires&amp;rdquo; medium {Hill, E.A. 2007}</td></tr><tr><td>Thioctic Acid</td><td>Sigma</td><td>T-1395</td><td>Used to make vitamin solution, used for &amp;ldquo;nanowires&amp;rdquo; medium {Hill, E.A. 2007}</td></tr></tbody></table>

in situ characterization of shewanella oneidensis mr1 biofilms by salvi and tof-sims

细菌生物被膜表面相关的社区大大研究了解他们自身产生的胞外聚合物 (EPS) 和在环境微生物学中的作用。本研究概述了培养生物膜附着到对系统进行分析在液体真空接口 （萨尔） 和飞行时间二次离子质谱 (TOF-SIMS) 实现原位化学映射的生活生物膜的方法。这样做是通过培养细菌外和内萨尔维通道与我们专门的安装程序，并通过光学成像技术来检测生物膜的存在和 TOF-SIMS 分析前的厚度。我们的研究结果表明希瓦氏菌生物膜的特征峰在其自然的水合状态，突出其本地化的水群集环境中，以及 EPS 片断，它们是截然不同的同一生物膜脱水状态。这些结果表明基于真空化学成像仪原位生物膜成像允许的萨尔的突破能力。

这些代表性的结果，足以说明如何可以识别和解释，附生物膜的化学特征，如通过 TOF-SIMS 获得。后密谋从 TOF-SIMS 数据采集，在程序部分，简要地强调质谱峰值识别应进行将标识分配给每个各自的 m/z 值。这可以通过广泛的文献回顾对质谱在细菌和预计中研究了等各种水团簇、 脂肪酸和蛋白质片段的细菌可能存在的特定化学片段。16,...

Watch this Scientific Journal Video about In Situ Characterization of Shewanella oneidensis MR1 Biofilms by SALVI and ToF-SIMS at JoVE.com

In Situ Characterization of Shewanella oneidensis MR1 Biofilms by SALVI and ToF-SIMS

这篇文章提出了不断增长的生物膜的原位飞行时间二次离子质谱的研究化学的映射在其水化状态下，由微流控反应器，在液体真空接口分析系统启用的方法。希瓦氏菌 oneidensis先生-1 与绿色荧光蛋白作为一种模型。

原位萨尔和 TOF-SIMS希瓦氏菌 oneidensis MR1 生物膜的表征

Bacterial biofilms are surface-associated communities that are vastly studied to understand their self-produced extracellular polymeric substances (EPS) ...

in-situ-characterization-shewanella-oneidensis-mr1-biofilms-salvi-tof

Research

JoVE Journal

Chemistry

In Situ Characterization of Shewanella oneidensis MR1 Biofilms by SALVI and ToF-SIMS

8.9K 次观看.  Pacific Northwest National Laboratory. 这篇文章提出了不断增长的生物膜的原位飞行时间二次离子质谱的研究化学的映射在其水化状态下，由微流控反应器，在液体真空接口分析系统启用的方法。希瓦氏菌 oneidensis先生-1 与绿色荧光蛋白作为一种模型。

视频: In Situ Characterization of Shewanella oneidensis MR1 Biofilms by SALVI and ToF-SIMS

Cell-Free DNA Integrity Analysis in Urine Samples

Although the presence of circulating cell-free DNA in plasma or serum has been widely shown to be a suitable source of biomarkers for many types of cancer, few studies have focused on the potential use of urine cell-free (UCF) DNA. Starting from the hypotheses that normal apoptotic cells produce highly fragmented DNA and that cancer cells release longer DNA, the potential role of UCF DNA integrity was evaluated as an early diagnostic marker capable of distinguishing between patients with prostate or bladder cancer and healthy individuals.
A UCF DNA integrity analysis is proposed on the basis of four quantitative real-time PCRs of four sequences longer than 250 bp: c-MYC, BCAS1, HER2, and AR. Sequences that frequently have an increased DNA copy number in bladder and prostate cancers were chosen for the analysis, but the method is flexible, and these genes could be substituted with other genes of interest. The potential utility of UCF DNA as a source of biomarkers has already been demonstrated for urologic malignancies, thus paving the way for further studies on UCF DNA characterization. The UCF DNA integrity test has the advantage of being non-invasive, rapid, and easy to perform, with only a few milliliters of urine needed to carry out the analysis.

A method for analyzing DNA integrity in the cell-free supernatant fraction of urine samples is proposed. The method is suitable for early detection of urological malignancies and has proven accurate for the early diagnosis of bladder cancer.

无细胞DNA完整性分析尿样中

Although the presence of circulating cell-free DNA in plasma or serum has been widely shown to be a suitable source of biomarkers for many types of ...

科研

癌症研究

In Situ SIMS and IR Spectroscopy of Well-defined Surfaces Prepared by Soft Landing of Mass-selected Ions

Soft landing of mass-selected ions onto surfaces is a powerful approach for the highly-controlled preparation of materials that are inaccessible using conventional synthesis techniques. Coupling soft landing with in situ characterization using secondary ion mass spectrometry (SIMS) and infrared reflection absorption spectroscopy (IRRAS) enables analysis of well-defined surfaces under clean vacuum conditions. The capabilities of three soft-landing instruments constructed in our laboratory are illustrated for the representative system of surface-bound organometallics prepared by soft landing of mass-selected ruthenium tris(bipyridine) dications, [Ru(bpy)3]2+ (bpy = bipyridine), onto carboxylic acid terminated self-assembled monolayer surfaces on gold (COOH-SAMs). In situ time-of-flight (TOF)-SIMS provides insight into the reactivity of the soft-landed ions. In addition, the kinetics of charge reduction, neutralization and desorption occurring on the COOH-SAM both during and after ion soft landing are studied using in situ Fourier transform ion cyclotron resonance (FT-ICR)-SIMS measurements. In situ IRRAS experiments provide insight into how the structure of organic ligands surrounding metal centers is perturbed through immobilization of organometallic ions on COOH-SAM surfaces by soft landing. Collectively, the three instruments provide complementary information about the chemical composition, reactivity and structure of well-defined species supported on surfaces.

In Situ SIMS and IR Spectroscopy of Well-defined Surfaces Prepared by Soft Landing of Mass-selected Ions

Soft landing of mass-selected ions onto surfaces is a powerful approach for the highly-controlled preparation of novel materials. Coupled with analysis by in situ secondary ion mass spectrometry (SIMS) and infrared reflection absorption spectroscopy (IRRAS), soft landing provides unprecedented insights into the interactions of well-defined species with surfaces.

在质谱选择离子软着陆准备好定义的表面原位二次离子质谱和红外光谱

Soft landing of mass-selected ions onto surfaces is a powerful approach for the highly-controlled preparation of materials that are inaccessible using ...

化学

Serum and Plasma Copy Number Detection Using Real-time PCR

Serum and plasma cell free DNA (cfDNA) has been shown as an informative, non-invasive source of biomarkers for cancer diagnosis, prognosis, monitoring, and prediction of treatment resistance. Starting from the hypothesis that androgen receptor (AR) gene copy number (CN) gain is a frequent event in metastatic castration resistance prostate cancer (mCRPC), we propose to analyze this event in cfDNA as a potential predictive biomarker.
We evaluated AR CN in cfDNA using 2 different real-time PCR assays and 2 reference genes (RNaseP and AGO1). DNA amount of 60 ng was used for each assay combination. AR CN gain was confirmed using Digital PCR as a more accurate method. CN variation analysis has already been demonstrated to be informative for the prediction of treatment resistance in the setting of mCRPC, but it could be useful also for other purposes in different patient settings. CN analysis on cfDNA has several advantages: it is non-invasive, rapid and easy to perform, and it starts from a small volume of serum or plasma material.

This manuscript describes the copy number variation analysis performed in serum or plasma DNA using real-time PCR approach. This method is suitable for the prediction of drug resistance in castration resistant prostate cancer patients, but it could be informative also for other diseases.

应用实时 PCR 技术检测血清和血浆拷贝数

Serum and plasma cell free DNA (cfDNA) has been shown as an informative, non-invasive source of biomarkers for cancer diagnosis, prognosis, monitoring, ...

Detection of a CDH1 Rare Transcript Variant in Fresh-frozen Gastric Cancer Tissues by Chip-based Digital PCR

CDH1a, a non-canonical transcript of the CDH1 gene, has been found to be expressed in some gastric cancer (GC) cell lines, whereas it is absent in normal gastric mucosa. Recently, we detected CDH1a transcript variant in fresh-frozen tumor tissues obtained from patients with GC. The expression of this variant in tissue samples was investigated by the chip-based digital PCR (dPCR) approach presented here. dPCR offers the potential for an accurate, robust, and highly sensitive measurement of nucleic acids and is increasingly utilized for many applications in different fields. dPCR is capable of detecting rare targets; in addition, dPCR offers the possibility for absolute and precise quantification of nucleic acids without the need for calibrators and standard curves. In fact, the reaction partitioning enriches the target from the background, which improves amplification efficiency and tolerance to inhibitors. Such characteristics make dPCR an optimal tool for the detection of the CDH1a rare transcript.

Detection of a CDH1 Rare Transcript Variant in Fresh-frozen Gastric Cancer Tissues by Chip-based Digital PCR

The manuscript describes a chip-based digital PCR assay to detect a rare CDH1 transcript variant (CDH1a) in fresh-frozen normal and tumor tissues obtained from patients with gastric cancer.

基于芯片的数字 PCR 检测新鲜冷冻胃癌组织中的一个CDH1罕见转录变体

CDH1a, a non-canonical transcript of the CDH1 gene, has been found to be expressed in some gastric cancer (GC) cell lines, whereas it is absent in normal ...

Assessment of Boron Doped Diamond Electrode Quality and Application to In Situ Modification of Local pH by Water Electrolysis

Boron doped diamond (BDD) electrodes have shown considerable promise as an electrode material where many of their reported properties such as extended solvent window, low background currents, corrosion resistance, etc., arise from the catalytically inert nature of the surface. However, if during the growth process, non-diamond-carbon (NDC) becomes incorporated into the electrode matrix, the electrochemical properties will change as the surface becomes more catalytically active. As such it is important that the electrochemist is aware of the quality and resulting key electrochemical properties of the BDD electrode prior to use. This paper describes a series of characterization steps, including Raman microscopy, capacitance, solvent window and redox electrochemistry, to ascertain whether the BDD electrode contains negligible NDC i.e. negligible sp2 carbon. One application is highlighted which takes advantage of the catalytically inert and corrosion resistant nature of an NDC-free surface i.e. stable and quantifiable local proton and hydroxide production due to water electrolysis at a BDD electrode. An approach to measuring the local pH change induced by water electrolysis using iridium oxide coated BDD electrodes is also described in detail.

Assessment of Boron Doped Diamond Electrode Quality and Application to In Situ Modification of Local pH by Water Electrolysis

A protocol is described for the characterization of the key electrochemical parameters of a boron doped diamond (BDD) electrode and subsequent application for in situ pH generation experiments.

掺硼金刚石电极质量和应用，以评估<em&gt;原位</em&gt;本地pH值通过水电改造

Boron doped diamond (BDD) electrodes have shown considerable promise as an electrode material where many of their reported properties such as extended ...

Radiolabeling and Quantification of Cellular Levels of Phosphoinositides by High Performance Liquid Chromatography-coupled Flow Scintillation

Phosphoinositides (PtdInsPs) are essential signaling lipids responsible for recruiting specific effectors and conferring organelles with molecular identity and function. Each of the seven PtdInsPs varies in their distribution and abundance, which are tightly regulated by specific kinases and phosphatases. The abundance of PtdInsPs can change abruptly in response to various signaling events or disturbance of the regulatory machinery. To understand how these events lead to changes in the amount of PtdInsPs and their resulting impact, it is important to quantify PtdInsP levels before and after a signaling event or between control and abnormal conditions. However, due to their low abundance and similarity, quantifying the relative amounts of each PtdInsP can be challenging. This article describes a method for quantifying PtdInsP levels by metabolically labeling cells with 3H-myo-inositol, which is incorporated into PtdInsPs. Phospholipids are then precipitated and deacylated. The resulting soluble 3H-glycero-inositides are further extracted, separated by high-performance liquid chromatography (HPLC), and detected by flow scintillation. The labeling and processing of yeast samples is described in detail, as well as the instrumental setup for the HPLC and flow scintillator. Despite losing structural information regarding acyl chain content, this method is sensitive and can be optimized to concurrently quantify all seven PtdInsPs in cells.

Phosphoinositides are signaling lipids whose relative abundance rapidly changes in response to various stimuli. This article describes a method to measure the abundance of phosphoinositides by metabolically labeling cells with 3H-myo-inositol, followed by extraction and deacylation. Extracted glycero-inositides are then separated by high-performance liquid chromatography and quantified by flow scintillation.

放射性标记和磷酸肌醇的细胞水平的定量高效液相色谱耦合流动闪烁

Phosphoinositides (PtdInsPs) are essential signaling lipids responsible for recruiting specific effectors and conferring organelles with molecular ...

In Situ Characterization of Hydrated Proteins in Water by SALVI and ToF-SIMS

This work demonstrates in situ characterization of protein biomolecules in the aqueous solution using the System for Analysis at the Liquid Vacuum Interface (SALVI) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The fibronectin protein film was immobilized on the silicon nitride (SiN) membrane that forms the SALVI detection area. During ToF-SIMS analysis, three modes of analysis were conducted including high spatial resolution mass spectrometry, two-dimensional (2D) imaging, and depth profiling. Mass spectra were acquired in both positive and negative modes. Deionized water was also analyzed as a reference sample. Our results show that the fibronectin film in water has more distinct and stronger water cluster peaks compared to water alone. Characteristic peaks of amino acid fragments are also observable in the hydrated protein ToF-SIMS spectra. These results illustrate that protein molecule adsorption on a surface can be studied dynamically using SALVI and ToF-SIMS in the liquid environment for the first time.

In Situ Characterization of Hydrated Proteins in Water by SALVI and ToF-SIMS

This work presents a protocol for liquid handling and sample introduction to a microchannel for in situ time-of-flight secondary ion mass spectrometry analysis of protein biomolecules in an aqueous solution.

在水中水合蛋白原位表征SALVI和TOF-SIMS

This work demonstrates in situ characterization of protein biomolecules in the aqueous solution using the System for Analysis at the Liquid Vacuum ...

Synthesis and Characterization of Supramolecular Colloids

Control over colloidal assembly is of utmost importance for the development of functional colloidal materials with tailored structural and mechanical properties for applications in photonics, drug delivery and coating technology. Here we present a new family of colloidal building blocks, coined supramolecular colloids, whose self-assembly is controlled through surface-functionalization with a benzene-1,3,5-tricarboxamide (BTA) derived supramolecular moiety. Such BTAs interact via directional, strong, yet reversible hydrogen-bonds with other identical BTAs. Herein, a protocol is presented that describes how to couple these BTAs to colloids and how to quantify the number of coupling sites, which determines the multivalency of the supramolecular colloids. Light scattering measurements show that the refractive index of the colloids is almost matched with that of the solvent, which strongly reduces the van der Waals forces between the colloids. Before photo-activation, the colloids remain well dispersed, as the BTAs are equipped with a photo-labile group that blocks the formation of hydrogen-bonds. Controlled deprotection with UV-light activates the short-range hydrogen-bonds between the BTAs, which triggers the colloidal self-assembly. The evolution from the dispersed state to the clustered state is monitored by confocal microscopy. These results are further quantified by image analysis with simple routines using ImageJ and Matlab. This merger of supramolecular chemistry and colloidal science offers a direct route towards light- and thermo-responsive colloidal assembly encoded in the surface-grafted monolayer.

A protocol for the synthesis and characterization of colloids coated with supramolecular moieties is described. These supramolecular colloids undergo self-assembly upon the activation of the hydrogen-bonds between the surface-anchored molecules by UV-light.

超分子胶体的合成与表征

Control over colloidal assembly is of utmost importance for the development of functional colloidal materials with tailored structural and mechanical ...

Preparation of Chloroplast Sub-compartments from Arabidopsis for the Analysis of Protein Localization by Immunoblotting or Proteomics

Chloroplasts are major components of plant cells. Such plastids fulfill many crucial functions, such as assimilation of carbon, sulfur and nitrogen as well as synthesis of essential metabolites. These organelles consist of the following three key sub-compartments. The envelope, characterized by two membranes, surrounds the organelle and controls the communication of the plastid with other cell compartments. The stroma is the soluble phase of the chloroplast and the main site where carbon dioxide is converted into carbohydrates. The thylakoid membrane is the internal membrane network consisting of grana (flat compressed sacs) and lamellae (less dense structures), where oxygenic photosynthesis takes place. The present protocol describes step by step procedures required for the purification, using differential centrifugations and Percoll gradients, of intact chloroplasts from Arabidopsis, and their fractionation, using sucrose gradients, in three sub-compartments (i.e., envelope, stroma, and thylakoids). This protocol also provides instructions on how to assess the purity of these fractions using markers associated to the various chloroplast sub-compartments. The method described here is valuable for subplastidial localization of proteins using immunoblotting, but also for subcellular and subplastidial proteomics and other studies.

Here, we describe a method to purify intact chloroplasts from Arabidopsis leaves and their three main sub-compartments (envelope, stroma, and thylakoids), using a combination of differential centrifugations, continuous Percoll gradients, and discontinuous sucrose gradients. The method is valuable for subplastidial and subcellular localization of proteins by immunoblotting and proteomics.

拟南芥叶绿体子隔层的制备及免疫印迹蛋白质组化分析

Chloroplasts are major components of plant cells. Such plastids fulfill many crucial functions, such as assimilation of carbon, sulfur and nitrogen as ...

生物化学

Physiological Preparation of Hair Cells from the Sacculus of the American Bullfrog (Rana catesbeiana)

The study of hearing and balance rests upon insights drawn from biophysical studies of model systems. One such model, the sacculus of the American bullfrog, has become a mainstay of auditory and vestibular research. Studies of this organ have revealed how sensory cells hair can actively detect signals from the environment. Because of these studies, we now better understand the mechanical gating and localization of a hair cell&#39;s transduction channels, calcium&#39;s role in mechanical adaptation, and the identity of hair cell currents. This highly accessible organ continues to provide insight into the workings of hair cells. Here we describe the preparation of the bullfrog&#39;s sacculus for biophysical studies on its hair cells. We include the complete dissection procedure and provide specific protocols for the preparation of the sacculus in specific contexts. We additionally include representative results using this preparation, including the calculation of a hair bundle&#39;s instantaneous force-displacement relation and measurement of a bundle&#39;s spontaneous oscillation.

Physiological Preparation of Hair Cells from the Sacculus of the American Bullfrog Rana catesbeiana

The American bullfrog&#39;s (Rana catesbeiana) sacculus permits direct examination of hair-cell physiology. Here the dissection and preparation of the bullfrog&#39;s sacculus for biophysical studies is described. We show representative experiments from these hair cells, including the calculation of a bundle&#39;s force-displacement relation and measurement of its unforced motion.

原位萨尔和 TOF-SIMS希瓦氏菌 oneidensis MR1 生物膜的表征

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