我们感谢建华岭，雷蒙德·麦克唐纳，高尔文斯威夫特，米歇尔·格里芬，保罗格里波和Satyanarayana Rachagani了他们的宝贵意见，建议和分享他们的协议。这项工作是由授出U01CA111294从俄亥俄州立大学院内研究计划的理念发展奖的支持。

1。准备以下做法坚持以该机构的动物护理和使用委员会（IACUC）设置的策略。 <ol><li>建议在隔离不超过6小鼠胰腺中任何一天。让所有的手术器械清洁和灭菌，每只动物一组。 </li><li>标记所有离心管。 4个2 ml离心管每只动物。 </li><li>放置8毫升裂解试剂在冰上的50ml离心管中。注意:当纯化试剂盒自带的硫氰酸胍酚试剂，适合于胰腺分离，裂解试剂使用，因为大量是每个隔离必要的。 </li><li>免除约10毫升以下解决方案集成到15ml离心管清洗均质机的叶片。乙醇，70％（2管），HPLC级水（1管）和HPLC级水约含200μLRNA酶的客场或同等核糖核酸酶灭活。 </li></oL&gt; 2，外科，胰腺解剖和同质化<ol><li>将1-2毫升的异氟醚为含棉纱布或纸巾罐。将小鼠放置于阻止他们到达异氟醚的源的平台。加入新鲜的异氟醚的麻醉罐每只小鼠前。 </li><li>轻轻将鼠标放到含有异氟醚的罐子。盖上瓶子并通过轻轻地转动瓶子来回监测麻醉的效果。动物被麻醉，一旦它在无法站立在它自己的。 </li><li>为了确认麻醉，从罐子里取出的动物和应用坚定的脚趾捏。如果鼠标没有反应到脚趾捏，继续执行步骤2.5。 </li><li>如果鼠标反应到脚趾捏，然后重复步骤2.2至2.3。 </li><li>将动物麻醉的台式俯卧位。紧紧把左手放在鼠标的子宫颈脱臼鼠标的子宫颈。我们ing的右手抓住老鼠的尾巴，快速地向上拉以大约45°角脱臼子宫颈。 </li><li>通过使用25号皮下注射针头的每个动物的四只爪子的刺入平坦面固定到胎体的表面（一个电平片发泡胶覆盖纸巾）。 </li><li>用无菌手术器械，切断小鼠的中部开，并迅速从小鼠取出胰腺。使用镊子举行胰腺和使用弹簧剪刀从脾脏和小肠切开它。要小心，不要从鼠标的拆卸过程中拉伸胰腺。组织破坏可能释放核糖核酸酶。注意:它需要从鼠标移除胰脏的时间是至关重要的。本领域技术人员应该能够解剖胰腺在约1分钟或更少。 </li><li>将整个胰腺入50毫升的试管装有8毫升冰冷的裂解试剂。盖上管，并简要摇沉浸在TISSUE到试剂和进行无延迟的下一个步骤。裂解试剂来组织的比例是至关重要的。看到结果的RNA的完整性使用不同体积的裂解试剂中分离出来的比较部分。 </li><li>匀化，持续5秒。它以按均质叶片的离心管的底部，以允许组织被拉到到叶片效率均匀化是重要的。 </li></ol> 3，去除未消化的组织的注意:以下均质化，组织的小的位将保持在裂解试剂。它快速裂解组织留下一些未消化的组织，而不是通过均质化和RNA的降解风险是比较重要的。 <ol><li>转让2毫升裂解试剂的含有溶解的胰腺2ml微量离心管中。收集每隔离匀浆两个离心管。倒掉剩余的匀浆或储存在-80°C为今后的研究。 </li><li>一分钱rifuge在4℃，12000×g离心5分钟以沉淀未消化的组织。这是一个重要的步骤，因为未消化的组织的残留成RNA的后续的解决方案可能会污染样品与核糖核酸（步骤5.13）。 </li><li>转让将1ml上清液到2ml微量离心管中。与隔离，立即进行和复制管储存于-80℃以备将来使用。放置装有匀浆于湿冰，而继续进行下一个步骤的所有管道。 </li><li>出售剩余裂解试剂到合适的化学废物容器。 </li></ol>在均质机叶片4。清洁<ol><li>前继续下一隔离，通过将它们放置在10毫升的70％乙醇清洗匀浆器叶片。激活有关的均化器进行20秒以除去组织可能被捕获在叶片任何块。 </li><li>用200μl的枪头移除留在均质机叶片的任何碎片。 </l我&gt; <li>水，一般核糖核酸酶失活和70％乙醇重复步骤4.1。用干净的金均质轴擦拭。 </li><li>对于其余的动物的胰腺隔离重复步骤2.1中，从每个动物单独的，而不是集中在RNA分离饲养的RNA。 </li></ol> 5，RNA分离下面的部分是相同的纯化试剂盒协议。纯化试剂盒的优点是，它会分离，包括小RNA的总RNA。 <ol><li>如果使用冷冻组织匀浆液，解冻湿冰上，静置在室温下5分钟。 </li><li>加入200μl氯仿，帽管，并用手用力摇动15秒。让所述管支架在室温下2-3分钟。 </li><li>离心15分钟，12,000×g离心，4°C。 </li><li>传送上层的水层到微量离心管中。加1.5倍体积的异丙醇，并通过上下吹打数次调匀。 </li><li>转让最多700微升的样品放入一个旋转柱是放置在2 ml收集管。盖上盖子，离心机在8000×g离心15秒在室温。 </li><li>弃去流过。 </li><li>重复步骤5.5-5.6，使用该样品的其余部分。 </li><li>加入700μlBuffer RWT到离心柱。离心15秒，8,000×g的。弃去流过。 </li><li>移液管将500μl缓冲液RPE到离心柱。离心15秒，8,000×g离心洗柱。弃去流过。 </li><li>加入500μl缓冲液RPE到离心柱。离心2分钟在8000 XG干柱。 </li><li>离心柱转移到1.5 ml离心管。吸取80微升核糖核酸酶的水直接喷在旋转柱膜。离心1分钟，在8000×g离心来洗脱RNA。 </li><li>加入1μlRNA酶抑制剂的RNA溶液。储存在-80°C或进行至5.13。 </li><li>为了验证RNA的完整性，首先计算RNA的conce使用分光光度计ntration和二百八十分之二百六十比。 </li><li>稀释的RNA溶液的一部分以约500纳克/微升用分子生物学级别水。 </li><li>确定RNA的完整性（ 即 RIN）利用毛细管电泳分析。约5微升RNA溶液是足够的分析。 </li><li>分装的RNA溶液（参见图2），并存储于-80℃。 </li></ol>

<ol><li>Chen, C., Ridzon, D. A., Broomer, A. J., Zhou, Z., Lee, D. H., Nguyen, J. T., Barbisin, M., Xu, N. L., Mahuvakar, V. R., Andersen, M. R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Real-time+quantification+of+microRNAs+by+stem-loop+RT-PCR%5BTitle%5D)+AND+%22Nucleic+Acids+Res%22%5BJournal%5D)">Real-time quantification of microRNAs by stem-loop RT-PCR.</a> Nucleic Acids Res. 33, e179(2005).</li>
<li>Chirgwin, J. M., Przybyla, A. E., MacDonald, R. J., Rutter, W. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Isolation+of+biologically+active+ribonucleic+acid+from+sources+enriched+in+ribonuclease%5BTitle%5D)+AND+%22Biochemistry%22%5BJournal%5D)">Isolation of biologically active ribonucleic acid from sources enriched in ribonuclease.</a> Biochemistry. 18, 5294-5299 (1979).</li>
<li>Chomczynski, P., Sacchi, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Single-step+method+of+RNA+isolation+by+acid+guanidinium+thiocyanate-phenol-chloroform+extraction%5BTitle%5D)+AND+%22Anal+Biochem%22%5BJournal%5D)">Single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction.</a> Anal Biochem. 162, 156-159 (1987).</li>
<li>Griffin, M., Abu-El-Haija, M., Abu-El-Haija, M., Rokhlina, T., Uc, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Simplified+and+versatile+method+for+isolation+of+high-quality+RNA+from+pancreas%5BTitle%5D)+AND+%22Biotechniques%22%5BJournal%5D)">Simplified and versatile method for isolation of high-quality RNA from pancreas.</a> Biotechniques. 52, 332-334 (2012).</li>
<li>Iyer, V. R., Eisen, M. B., Ross, D. T., Schuler, G., Moore, T., Lee, J. C., Trent, J. M., Staudt, L. M., Hudson Jr, J., Boguski, M. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((The+transcriptional+program+in+the+response+of+human+fibroblasts+to+serum%5BTitle%5D)+AND+%22Science%22%5BJournal%5D)">The transcriptional program in the response of human fibroblasts to serum.</a> Science. 283, 83-87 (1999).</li>
<li>Lenstra, J. A., Beintema, J. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((The+amino+acid+sequence+of+mouse+pancreatic+ribonuclease.+Extremely+rapid+evolutionary+rates+of+the+myomorph+rodent+ribonucleases%5BTitle%5D)+AND+%22European+journal+of+biochemistry++FEBS%22%5BJournal%5D)">The amino acid sequence of mouse pancreatic ribonuclease. Extremely rapid evolutionary rates of the myomorph rodent ribonucleases.</a> European journal of biochemistry FEBS. 98, 399-408 (1979).</li>
<li>Mullin, A. E., Soukatcheva, G., Verchere, C. B., Chantler, J. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Application+of+in+situ+ductal+perfusion+to+facilitate+isolation+of+high-quality+RNA+from+mouse+pancreas%5BTitle%5D)+AND+%22Biotechniques%22%5BJournal%5D)">Application of in situ ductal perfusion to facilitate isolation of high-quality RNA from mouse pancreas.</a> Biotechniques. 40, 617-621 (2006).</li>
<li>Rio, D. C., Ares, M., Hannon, G. J., Nilsen, T. W. <a target="_blank" href="http://scholar.google.com/scholar?hl=en&safe=off&q=author%3aRio%2C+DC+%22RNA+A+Laboratory+Manual%22">RNA A Laboratory Manual</a>. , Cold Springs Harbor Laboratory Press. Cold Springs Harbor, NY. (2011).</li>
<li>Streit, S., Michalski, C. W., Erkan, M., Kleeff, J., Friess, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Northern+blot+analysis+for+detection+and+quantification+of+RNA+in+pancreatic+cancer+cells+and+tissues%5BTitle%5D)+AND+%22Nat+Protoc%22%5BJournal%5D)">Northern blot analysis for detection and quantification of RNA in pancreatic cancer cells and tissues.</a> Nat Protoc. 4, 37-43 (2009).</li>
<li>Zmuda, E. J., Powell, C. A., Hai, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((A+method+for+murine+islet+isolation+and+subcapsular+kidney+transplantation%5BTitle%5D)+AND+%22Journal+of+Visualized+Experiments++JoVE%22%5BJournal%5D)">A method for murine islet isolation and subcapsular kidney transplantation.</a> Journal of Visualized Experiments JoVE. , (2011).</li>
</ol>

The authors have nothing to disclose.

从被核糖核酸酶丰富的组织中分离RNA代表了分子生物学实验的一大挑战。各种试剂和试剂盒是市售的主要依据RNA提取的酚异硫氰酸胍法。硫氰酸胍变性蛋白，从而减少核糖核酸酶的活性。然而，核糖核酸酶在胰腺的庞大规模需要额外的修改，RNA分离标准协议。协议是在这里报道，基于标准的异硫氰酸胍法还包含几个关键的改进，以及提示RNA的核糖核酸酶丰富的组织如胰腺成功分离。 <p class="jove...

需要常规的分子生物学实验，如Northern印迹9，定量RT-PCR检测1或基因表达谱5与诚信度高的RNA分离。大多数现代的RNA分离方法，是根据对硫氰酸胍协议2，修改3。硫氰酸胍是一种强的蛋白质变性剂，并有效地破坏大多数条件下核糖核酸酶的活性。 Chomczynski和Sacchi 3的流行的方法结合到苯酚的硫氰酸胍裂解溶液，减少了隔离时间约4小时。许多市售的RNA提取试剂基于Chomczynski和Sacchi方法3。 核糖核酸酶丰富的组织如人类或小鼠胰腺呈现为分离RNA一个额外的挑战。小鼠胰腺可含有高达75毫克核糖核酸酶6的其中一些将被释放超级碗造成组织自溶胰腺组织克中断。的异硫氰酸胍协议的修改已经被成功地用于分离RNA从胰腺具有高完整性2，4，7，10，输液RNA稳定剂与高完整性4，7，10的RNA小鼠胰腺促进隔离的，但是输注解决方案集成到胰腺需要很高的技巧，可能需要专门的工具，如解剖显微镜和手术过程中破坏的组织架构，可能会导致细胞裂解。组织灌注与RNA的稳定剂可能干扰其他应用，包括蛋白分离和组织学染色。此外，这种技术不适合于从人胰腺中分离RNA。其他协议需要由研究者2编制具体的解决方案。 我们报告一个协议来分离RNA从小鼠胰腺诚信度高。钍Ë协议使用先前公布的方法要素，并在很大程度上基于标准的酚/异硫氰酸胍基裂解试剂的协议。它不需要专门的解决方案的准备，也不需要输液剂进入胰腺。对于成功的RNA分离的关键步骤包括一个高酚/胍基裂解试剂对组织的比例，除去相分离和包容核糖核酸酶抑制剂到所得到的RNA溶液先未消化的组织。使用这些和其它的修改，我们通常分离RNA与RIN大于7被用于常规的基因表达分析。

<table><tbody><tr><td>Power Gen 500&amp;nbsp;</td><td>Fisher Scientific</td><td>14-261-03&amp;nbsp;</td><td>Homogenizer</td></tr><tr><td>5424R</td><td>Eppendorf</td><td></td><td>Refrigerated microcentifuge</td></tr><tr><td>Trizol reagent</td><td>Invitrogen</td><td>15596018</td><td>Lysis reagent</td></tr><tr><td>Student Vannas spring scissors</td><td>Fisher</td><td>91500-09&amp;nbsp;</td><td>Use to cut pancreas from attached tissues</td></tr><tr><td>Surgical scissors, 6 inch</td><td>Fisher</td><td>08-951-20</td><td>Use to cut scin of mouse</td></tr><tr><td>Blunt end forceps</td><td>Fisher</td><td>1381239</td><td>Use to hold pancreas while dissecting</td></tr><tr><td>Isoflurane USP</td><td>Abbott Labs</td><td>4/8/5210</td><td>Anesthetic</td></tr><tr><td>Rnase out (40 U/&amp;micro;l)</td><td>Invitrogen</td><td>10777-019</td><td>Rnase inhbitor</td></tr><tr><td>Rnase Away</td><td>Ambion</td><td>10328-011</td><td>General Rnase inactivator</td></tr><tr><td>HPLC grade water</td><td>Fisher</td><td>W5-4</td><td>For washing homogenizer blades</td></tr><tr><td>Molecular biology grade water</td><td>Hyclone</td><td>SH30538.03</td><td>Elution of RNA</td></tr><tr><td>miRNeasy Mini kit</td><td>Qiagen</td><td>217004</td><td>Purification Kit</td></tr><tr><td>2 ml microcentrifuge tubes, certified Rnase Dnase free</td><td>USA Scientific Plastics</td><td>1620-2700</td><td></td></tr><tr><td>15 ml centrifuge tubes</td><td>Falcon</td><td>352099</td><td></td></tr><tr><td>70% ethanol</td><td>Fisher</td><td></td><td></td></tr><tr><td>100% ethanol</td><td>Fisher</td><td></td><td></td></tr><tr><td>200 &amp;micro;l pipet tips</td><td>Rainin</td><td>GPL200F</td><td>For cleaning homogenizer blades</td></tr><tr><td>Chloroform</td><td>Fisher</td><td>BP1145-1</td><td></td></tr><tr><td>Nanodrop</td><td>Thermo</td><td>ND-1000</td><td>Spectrophotometer</td></tr><tr><td>Bioanalyzer</td><td>Agilent</td><td></td><td>Capillary electrophoresis analyzer to measue RNA integrity</td></tr><tr><td>RNAlater</td><td>Ambion</td><td></td><td>RNA Stabilization Reagent&amp;nbsp;</td></tr><tr><td>RNeasy&amp;nbsp;spin columns&amp;nbsp;</td><td>Qiagen</td><td></td><td>Spin columns&amp;nbsp;as a part of the miRNeasy Mini kit</td></tr><tr><td>Mice</td><td>Chales River</td><td>Strain C57BL/6</td><td>Their age ranged from 4 to 12 months.&amp;nbsp;&amp;nbsp;</td></tr><tr><td>Mice&amp;nbsp;</td><td>Jackson Lab</td><td>strain 129</td><td>Their age ranged from 4 to 12 months.&amp;nbsp;&amp;nbsp;</td></tr></tbody></table>

rna isolation from mouse pancreas: a ribonuclease-rich tissue

Isolation of high-quality RNA from ribonuclease-rich tissue such as mouse pancreas presents a challenge. As a primary function of the pancreas is to aid in digestion, mouse pancreas may contain as much a 75 mg of ribonuclease. We report modifications of standard phenol/guanidine thiocyanate lysis reagent protocols to isolate RNA from mouse pancreas. Guanidine thiocyanate is a strong protein denaturant and will effectively disrupt the activity of ribonuclease under most conditions. However, critical modifications to standard protocols are necessary to successfully isolate RNA from ribonuclease-rich tissues. Key steps include a high lysis reagent to tissue ratio, removal of undigested tissue prior to phase separation and inclusion of a ribonuclease inhibitor to the RNA solution. Using these and other modifications, we routinely isolate RNA with RNA Integrity Number (RIN) greater than 7. The isolated RNA is of suitable quality for routine gene expression analysis. Adaptation of this protocol to isolate RNA from ribonuclease rich tissues besides the pancreas should be readily achievable.

从1毫升裂解匀浆的总RNA得率是20〜40微克。外径260/280的比例通常约为2.0和RIN比7.0更加一致。如果RIN是≤6，隔离将需要被重复。有时，RIN，比8.0更高的实现。 去除之前的胰腺实施安乐死的小鼠的两种最常用的方法是CO 2窒息或吸入异氟醚。后跟颈椎脱位两种技术。因为它是可能的化学剂和/或程序时，可能会影响RNA的完整性，用这两种方法进行了比较分离小鼠胰腺核糖核...

Watch this Scientific Journal Video about RNA Isolation from Mouse Pancreas: A Ribonuclease-rich Tissue at JoVE.com

RNA Isolation from Mouse Pancreas: A Ribonuclease-rich Tissue

We report a procedure to isolate RNA with high integrity from the ribonuclease rich mouse pancreas.

从小鼠胰腺RNA提取:核糖核酸酶丰富的组织

Isolation of high-quality RNA from ribonuclease-rich tissue such as mouse pancreas presents a challenge.  As a primary function of the pancreas is to aid ...

rna-isolation-from-mouse-pancreas-a-ribonuclease-rich-tissue

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27.5K 次观看.  The Ohio State University. We report a procedure to isolate RNA with high integrity from the ribonuclease rich mouse pancreas.

视频: RNA Isolation from Mouse Pancreas: A Ribonuclease-rich Tissue

Murine Pancreatic Islet Isolation

Hi, I am Greg Zott. I'm with the UCSF Diabetes Center in the Bluestone Laboratory, and today I'm gonna show you the process for isolating mouse eyelets. The procedure involves the injection of a collagenase solution into the pancreas of a C3 H donor mouse, where we will then remove that pancreas, digest it away, purify the eyelets on a fial gradient, and then handpick them for ultimate transplant into the kidney capsule of a diabetic NOD mouse, Which will be our recipient.Before we start this procedure, we diluted our ATE solution in a modified Hanks buffer and we have adjusted the concentration specific for the strain of mouse that we're using the C3 H.We found digests better at a 0.8 mgs per mil collagenase solution, and we will use that to inject into the common bile duct to distend the pancreas.Performing. The procedure today Will be Pavo codre of the diabetes center. He will inject, open up the mouse, expose the the intestines, and then inject into the common bile duct.We will spray down the mouse with ethanol to keep the hair down, and then we will also verify that the mouse has been sacrificed properly with a toe pinch. Pavo will now open up the mouse and exposing the intestine and the pancreas with a midline incision. The diaphragm will also be cut to verify that the mouse will be sacrificed.Before we get started, I'd like to point out some of the important structures. The stomach is lying right here with the pancreas attached underneath into the duodenum and above. This is the liver where we'll find the gallbladder and the common bile duct, which you can see right here.So what Pavo will do next is he will isolate the small intestine, find where the common bile duct enters the small intestine. Once the intestine is exposed, we clamp on either side of the common bile duct with mosquito clamps. We find that this allows more collagenates to enter the pancreas while other groups try to direct the clamp on top of the common bile duct.We find that this is a better technique in allowing enzyme to enter the pancreas. This is a gentle procedure. You don't want to tear the bowel.You wanna allow the clamps to lie gently on either side of the common bile duct. Now we will find a gallbladder, and once the gallbladder's exposed, we will use that as a guide to injecting the collagenase into the common bile duct. Powell's using a 30 gauge needle with a five cc syringe containing three mills of collagenase solution.As he's entering the common bile duct, he's distending that duct with collagenase solution and then he travels down the common bile duct till he reaches near the intestine. And as he's going down, the enzyme solutions being pumped into the injected into the pancreas. Now that the pancreas is inflated with collagenase solution, Powell's gonna remove the hemostats and then remove the pancreas from the the mouse carefully tearing it away from the intestine.He removes it from the stomach. Okay, and then using the spleen as a handle, he lifts up the pancreas and then slowly snips it away in the common bile duct, and that's it. Pancreas is laid out and then the spleen is removed, and there he's removing the meso enteric tissue, and then the pancreas is placed in a two mill collagenase solution and a sterilized glass vial and it's placed back on Ice.The isolated pancreas that we put into the glass vials will now be placed into a 37 degree water bath for approximately 17 minutes. We placed them into a 50 mil conical rack so that they don't float up. Once during the bath, the timer starts and the digestion begins.Once the digestion time is completed, vials are removed, and then they are shaken and disrupted gently. And once the tissue starts falling apart, the vial is then placed on ice. A sterile screen is placed over a 400 mil beaker that contains washing buffer.The pancreas digest is then carefully poured over the screen into the wash buffer. For demonstration purposes, the hood has been turned off and the glass of the hood has been raised so we could see what we're doing. Once the pancreas digest is poured into the beaker, the vials are rinsed with the same washing buffer and the wash buffer placed over the screen.We have a syringe filled with washing buffer. We will use that to forcefully wash the tissue through the screen. The idea is to release any loose eyelets that are unattached to the matrix, but leaving the membranes and the undigested tissue on the screen.And when you're finished washing a tissue, this is what you usually See at the end of the procedure. The Pancreas tissue that's in the bottom of the tube will now be transferred to two 50 mil conical, and the tissue will be washed, the tissue's mixed evenly, and then distributed evenly so that we have a equal pellet volume in each tube. The beaker is now rinsed with more washing buffer.The sides are rinse so that you get all tissue that is entered the beaker again. Then it's equally distributed between each two, both 50 mil. Conical then are topped off with wash buffer.The tissue is inverted several times and then placed into a centrifuge. This is a quick spin. The centrifuge is allowed to reach a thousand RPM and then is turned off.The tissue at this time is very S eyelets are very sensitive, and you don't want to over compact them. The tubes are removed and we will do this wash step three more times. This is the end of the third wash.The components of the 50 mil conical tube are transferred to the 15 conical tube and centrifuge for a thousand RP M and then stopped. The supernat will be removed and the first part of the FI Call will be started. We are at the step where we Have our pelleted di pancreas digest.We'll resuspend that tissue so it's nice and loose to the pellets. We'll add the first density gradient, which is 1 1 0 8. We'll add five mils to each tube.The pellet is then mixed thoroughly in each of the gradients. It's important that you get good tissue distribution in your heaviest gradient. Now we will layer two mils of 1 0 9 6 density.We will then on top of that, layer two mils of 1 0 6 9 density, and then on top of that 1 0 3 7 density. It's important while you're layering the densities that you don't mix. Then all the layers have been added to the tube.And you can see this is the top of 1 1 0 8, the top of 9 1 0 9 6, the top of 1 0 6 9 and the top of 1 0 3 7. And you could see the tissue is already starting to move to its proper density even without centri fusion. The fial gradients are brought up to speed at 1800 RPM for 15 minutes, and remember to keep the brake off after the tubes are removed from the centrifuge.You can see between the 0 0 9 6 and 0 0 7 layer, there's a nice band of eyelet tissue Pablo's. Now removing the 0 3 7 layer to remove any tissue debris and DNA that might have been released during the processing. Using a sterile plastic pasture pipette, he will now remove the islet layer and transfer them to a 50 mil conical containing 25 mils of wash buffer.You want do this step quickly because fol is toxic to eyelets. We actually removed the entire 0 6 9 and 0 9 6 layer. Pavo cuts the top of the plastic pasture pipette and rinses it with wash buffer.The eyelets are then centrifuge like we centrifuge previously. Centrifuge is brought up to a Thousand RPM and then we stop it and We aspirate off. The supernatant eyelets will be washed three times with wash media.So we just completed the eyelid Isolation process we took from the digest to the fol gradient to the purified eyelets after our third wash with wash buffer, we resuspended the eyelets in our RPMI media and we played it in a tissue culture plate. These eyelets are now ready for in vitro assays or in vivo preps like eyelet Transplant.

小鼠胰岛隔离

科研

生物学

In Vitro Colony Assays for Characterizing Tri-potent Progenitor Cells Isolated from the Adult Murine Pancreas

Stem and progenitor cells from the adult pancreas could be a potential source of therapeutic beta-like cells for treating patients with type 1 diabetes. However, it is still unknown whether stem and progenitor cells exist in the adult pancreas. Research strategies using cre-lox lineage-tracing in adult mice have yielded results that either support or refute the idea that beta cells can be generated from the ducts, the presumed location where adult pancreatic progenitors may reside. These in vivo cre-lox lineage-tracing methods, however, cannot answer the questions of self-renewal and multi-lineage differentiation-two criteria necessary to define a stem cell. To begin addressing this technical gap, we devised 3-dimensional colony assays for pancreatic progenitors. Soon after our initial publication, other laboratories independently developed a similar, but not identical, method called the organoid assay. Compared to the organoid assay, our method employs methylcellulose, which forms viscous solutions that allow the inclusion of extracellular matrix proteins at low concentrations. The methylcellulose-containing assays permit easier detection and analyses of progenitor cells at the single-cell level, which are critical when progenitors constitute a small sub-population, as is the case for many adult organ stem cells. Together, results from several laboratories demonstrate in vitro self-renewal and multi-lineage differentiation of pancreatic progenitor-like cells from mice. The current protocols describe two methylcellulose-based colony assays to characterize mouse pancreatic progenitors; one contains a commercial preparation of murine extracellular matrix proteins and the other an artificial extracellular matrix protein known as a laminin hydrogel. The techniques shown here are 1) dissociation of the pancreas and sorting of CD133+Sox9/EGFP+ ductal cells from adult mice, 2) single cell manipulation of the sorted cells, 3) single colony analyses using microfluidic qRT-PCR and whole-mount immunostaining, and 4) dissociation of primary colonies into single-cell suspensions and re-plating into secondary colony assays to assess self-renewal or differentiation.

In Vitro Colony Assays for Characterizing Tri-potent Progenitor Cells Isolated from the Adult Murine Pancreas

In vitro colony assays to detect self-renewal and differentiation of progenitor cells isolated from adult murine pancreas are devised. In these assays, pancreatic progenitors give rise to cell colonies in 3-dimensional space in methylcellulose-containing semi-solid medium. Protocols for handling single cells and characterization of individual colonies are described.

体外测定菌落为表征的三效祖细胞从成人胰腺小鼠隔离

Stem and progenitor cells from the adult pancreas could be a potential source of therapeutic beta-like cells for treating patients with type 1 diabetes. ...

发育生物学

Effective Isolation of Functional Islets from Neonatal Mouse Pancreas

Perfusion-based islet-isolation protocols from large mammalian pancreata are well established. Such protocols are readily conducted in many laboratories due to the large size of the pancreatic duct that allows for ready collagenase injection and subsequent tissue perfusion. In contrast, islet isolation from small pancreata, like that of neonatal mice, is challenging because perfusion is not readily achievable in the small pancreata. Here we describe a detailed simple procedure that recovers substantial numbers of islets from newly born mice with visual assistance. Freshly dissected whole pancreata were digested with 0.5 mg/mL collagenase IV dissolved in Hanks&#39; Balanced Salt Solution (HBSS) at 37 &#176;C, in microcentrifuge tubes. Tubes were tapped regularly to aid tissue dispersal. When most of the tissue was dispersed to small clusters around 1 mm, lysates were washed three to four times with culture media with 10% fetal bovine serum (FBS). Islet clusters, devoid of recognizable acinar tissues, can then be recovered under dissecting stereoscope. This method recovers 20 - 80 small- to large-sized islets per pancreas of newly born mouse. These islets are suitable for most conceivable downstream assays, including insulin secretion, gene expression, and culture. An example of insulin secretion assay is presented to validate the isolation process. The genetic background and degree of digestion are the largest factors determining the yield. Freshly made collagenase solution with high activity is preferred, as it aids in endocrine-exocrine isolation. The presence of cations [calcium (Ca2+) and magnesium (Mg2+)] in all solutions and fetal bovine serum in the wash/picking media are necessary for good yield of islets with proper integrity. A dissecting scope with good contrast and magnification will also help.

We describe a protocol herein for isolating intact islets from neonatal mice. Pancreata were partially digested with collagenase, followed by washing and hand picking. 20 - 80 islet clusters can be obtained per pancreas from newly born mice, which are suitable for several islet studies.

新生小鼠胰腺胰岛功能的有效隔离

Perfusion-based islet-isolation protocols from large mammalian pancreata are well established. Such protocols are readily conducted in many laboratories ...

Single-cell RNA Sequencing and Analysis of Human Pancreatic Islets

Pancreatic islets comprise of endocrine cells with distinctive hormone expression patterns. The endocrine cells show functional differences in response to normal and pathological conditions. The goal of this protocol is to generate high-quality, large-scale transcriptome data of each endocrine cell type with the use of a droplet-based microfluidic single-cell RNA sequencing technology. Such data can be utilized to build the gene expression profile of each endocrine cell type in normal or specific conditions. The process requires careful handling, accurate measurement, and rigorous quality control. In this protocol, we describe detailed steps for human pancreatic islets dissociation, sequencing, and data analysis. The representative results of about 20,000 human single islet cells demonstrate the successful application of the protocol.

Here, we present a protocol to generate high-quality, large-scale transcriptome data of single cells from isolated human pancreatic islets using a droplet-based microfluidic single-cell RNA sequencing technology.

人类胰腺胰岛的单细胞RNA测序与分析

Pancreatic islets comprise of endocrine cells with distinctive hormone expression patterns. The endocrine cells show functional differences in response to ...

遗传学

Rapid and Cost-Effective RNA Extraction of Rat Pancreatic Tissue

Regardless of the extraction method, optimized RNA extraction of tissues and cell lines are carried out in four stages: 1) homogenization, 2) effective denaturation of proteins from RNA, 3) ribonuclease inactivation, and 4) removal of contamination from DNA, proteins, and carbohydrates. However, it is very laborious to maintain the integrity of RNA when there are high levels of RNase in the tissue. Spontaneous autolysis makes it very difficult to extract RNA from pancreatic tissue without damaging it. Thus, a practical RNA extraction method is needed to maintain the integrity of pancreatic tissues during the extraction process. An experimental and comparative study of existing protocols was carried out by obtaining 20-30 mg of rat pancreatic tissues in less than 2 minutes and extracting the RNA. The results were assessed by electrophoresis. The experiments were carried out three times for generalization of the results. Immersing pancreatic tissue in RNA stabilization reagent at -80 &#176;C for 24 h yielded high integrity RNA, when the RNA extraction reagent was used as the reagent. The results obtained were comparable to the results obtained from commercial kits with spin column bindings.

The purity and integrity of the isolated RNA is a vital step in RNA dependent assays. Here, we present a practical, rapid, and inexpensive method to extract RNA from a small quantity of undamaged pancreatic tissue.

大鼠胰腺组织快速、经济高效的RNA提取

Regardless of the extraction method, optimized RNA extraction of tissues and cell lines are carried out in four stages: 1) homogenization, 2) effective ...

生物化学

Single-cell Transcriptomic Analyses of Mouse Pancreatic Endocrine Cells

Pancreatic endocrine cells, which are clustered in islets, regulate blood glucose stability and energy metabolism. The distinct cell types in islets, including insulin-secreting &#946; cells, are differentiated from common endocrine progenitors during the embryonic stage. Immature endocrine cells expand via cell proliferation and mature during a long postnatal developmental period. However, the mechanisms underlying these processes are not clearly defined. Single-cell RNA-sequencing is a promising approach for the characterization of distinct cell populations and tracing cell lineage differentiation pathways. Here, we describe a method for the single-cell RNA-sequencing of isolated pancreatic &#946; cells from embryonic, neonatal and postnatal pancreases.

We describe a method for the isolation of endocrine cells from embryonic, neonatal and postnatal pancreases followed by single-cell RNA sequencing. This method allows analyses of pancreatic endocrine lineage development, cell heterogeneity and transcriptomic dynamics.

小鼠胰腺内分泌细胞的单细胞 Transcriptomic 分析

Pancreatic endocrine cells, which are clustered in islets, regulate blood glucose stability and energy metabolism. The distinct cell types in islets, ...

Mouse Islet of Langerhans Isolation using a Combination of Purified Collagenase and Neutral Protease

The interrogation of beta cell gene expression and function in vitro has squarely shifted over the years from the study of rodent tumorigenic cell lines to the study of isolated rodent islets. Primary islets offer the distinct advantage that they more faithfully reflect the biology of intracellular signaling pathways and secretory responses. Whereas the method of islet isolation using tissue dissociating enzyme (TDE) preparations has been well established in many laboratories1-4, variations in the consistency of islet yield and quality from any given rodent strain limit the extent and feasibility of primary islet studies. These variations often occur as a result of the crude partially purified TDEs used in the islet isolation procedure; TDEs frequently exhibit lot-to-lot variations in activity and often require adjustments to the dose of enzyme used. A small number of reports have used purified TDEs for rodent cell isolations5, 6, but the practice is not widespread despite the routine use and advantages of purified TDEs for human islet isolations. In collaboration with VitaCyte, LLC (Indianapolis, IN), we developed a modified mouse islet isolation protocol based on that described by Gotoh7, 8, in which the TDEs are perfused directly into the pancreatic duct of mice, followed by crude tissue fractionation through a Histopaque gradient9, and isolation of purified islets. A significant difference in our protocol is the use of purified collagenase (CIzyme MA) and neutral protease (CIzyme BP) combination. The collagenase was characterized by the use of a6 fluorescence collagen degrading activity (CDA) assay that utilized fluorescently labeled soluble calf skin fibrils as substrate6. This substrate is more predictive of the kinetics of collagen degradation in the tissue matrix because it relies on native collagen as the substrate. The protease was characterized with a sensitive fluorescent kinetic assay10. Utilizing these improved assays along with more traditional biochemical analysis enable the TDE to be manufactured more consistently, leading to improved performance consistency between lots. The protocol described in here was optimized for maximal islet yield and optimal islet morphology using C57BL/6 mice. During the development of this protocol, several combinations of collagenase and neutral proteases were evaluated at different concentrations, and the final ratio of collagenase:neutral protease of 35:10 represents enzyme performance comparable to Sigma Type XI. Because significant variability in average islet yields from different strains of rats and mice have been reported, additional modifications of the TDE composition should be made to improve the yield and quality of islets recovered from different species and strains.

A detailed description of mouse islet isolation is described using the technique of in situ pancreatic ductal cannulation and perfusion of a combination of purified collagenase and neutral protease.

小鼠胰岛的朗格汉斯的分离纯化的胶原酶和中性蛋白酶结合使用

The interrogation of beta cell gene expression and function in vitro has squarely shifted over the years from the study of rodent tumorigenic cell lines ...

A Method for Mouse Pancreatic Islet Isolation and Intracellular cAMP Determination

Uncontrolled glycemia is a hallmark of diabetes mellitus and promotes morbidities like neuropathy, nephropathy, and retinopathy. With the increasing prevalence of diabetes, both immune-mediated type 1 and obesity-linked type 2, studies aimed at delineating diabetes pathophysiology and therapeutic mechanisms are of critical importance. The &#946;-cells of the pancreatic islets of Langerhans are responsible for appropriately secreting insulin in response to elevated blood glucose concentrations. In addition to glucose and other nutrients, the &#946;-cells are also stimulated by specific hormones, termed incretins, which are secreted from the gut in response to a meal and act on &#946;-cell receptors that increase the production of intracellular cyclic adenosine monophosphate (cAMP). Decreased &#946;-cell function, mass, and incretin responsiveness are well-understood to contribute to the pathophysiology of type 2 diabetes, and are also being increasingly linked with type 1 diabetes. The present mouse islet isolation and cAMP determination protocol can be a tool to help delineate mechanisms promoting disease progression and therapeutic interventions, particularly those that are mediated by the incretin receptors or related receptors that act through modulation of intracellular cAMP production. While only cAMP measurements will be described, the described islet isolation protocol creates a clean preparation that also allows for many other downstream applications, including glucose stimulated insulin secretion, [3H]-thymidine incorporation, protein abundance, and mRNA expression.

Assaying in vitro &#946;-cell function using isolated mouse islets of Langerhans is an important component in the study of diabetes pathophysiology and therapeutics. While many&#160;downstream applications are available, this protocol specifically describes the measurement of intracellular cyclic adenosine monophosphate (cAMP) as an essential parameter determining &#946;-cell function.

对小鼠胰腺胰岛分离和细胞内cAMP的测定方法

Uncontrolled glycemia is a hallmark of diabetes mellitus and promotes morbidities like neuropathy, nephropathy, and retinopathy. With the increasing ...

Isolation and Culture of Mouse Primary Pancreatic Acinar Cells

This protocol permits rapid isolation (in less than 1 hr) of murine pancreatic acini, making it possible to maintain them in culture for more than one week. More than 20 x 106 acinar cells can be obtained from a single murine pancreas. This protocol offers the possibility to independently process as many as 10 pancreases in parallel. Because it preserves acinar architecture, this model is well suited for studying the physiology of the exocrine pancreas in vitro in contrast to cell lines established from pancreatic tumors, which display many genetic alterations resulting in partial or total loss of their acinar differentiation.

In this publication, we describe a rapid and convenient procedure for isolating and culturing primary pancreatic acinar cells from the murine pancreas. This method constitutes a valuable approach to study the physiology of fresh primary normal/untransformed exocrine pancreatic cells.

小鼠原代胰腺腺泡细胞的分离和培养

This protocol permits rapid isolation (in less than 1 hr) of murine pancreatic acini, making it possible to maintain them in culture for more than one ...

A Simple High Efficiency Protocol for Pancreatic Islet Isolation from Mice

Pancreatic islets, also called the Islets of Langerhans, are a cluster of endocrine cells which produces hormones for glucose regulation and other important biological functions. The islets primarily consist of five types of hormone-secreting cells: &#945; cells secrete glucagon, &#946; cells secrete insulin, &#948; cells secrete somatostatin, &#949; cells secrete ghrelin, and PP cells secrete pancreatic polypeptide. Sixty to 80% of the cells in the islets are &#946; cells, which are the most important cell population to study insulin secretion. Pancreatic islets are a crucial model system to study ex vivo insulin secretion. Acquiring high quality islets is of great importance for diabetes research. Most islet isolation procedures require technically difficult to access site of collagenase injection, harsh and complex digestion procedures, and multiple density gradient purification steps. This paper features a simple high yield mouse islet isolation method with detailed descriptions and realistic demonstrations, showing the following specific steps: 1) injection of collagenase P at the ampulla of Vater, a small area joining the pancreatic duct and the common bile duct, 2) enzymatic digestion and mechanical separation of the exocrine pancreas, and 3) a single gradient purification step. The advantages of this method are the injection of digestive enzyme using the more accessible ampulla of Vater, more complete digestion using combination of enzymatic and mechanical approaches, and a simpler single gradient purification step. This protocol produces approximately 250&#8212;350 islets per mouse; and islets are suitable for various ex vivo studies. Possible caveats of this procedure are potentially damaged islets due to enzymatic digestion and/or prolonged gradient incubation, all of which can be largely avoided by careful ad justification of incubation time.

This islet isolation protocol described a novel route of collagenase injection to digest the exocrine tissue and a simplified gradient procedure to purify the islets from mice. It involves enzymatic digestion, gradient separation/purification, and islet hand-picking. Successful isolation can yield 250&#8211;350 high quality and fully functional islets per mouse.