我们要感谢李实验室的成员对稿件有价值的讨论。在李的实验室工作是由纽约干细胞基金会罗伯逊研究奖和美国马里兰干细胞研究基金（TEDCO）资助。

一个96孔板的1。下游<ol><li>混合1μL单细胞DNase1至9微升单细胞裂解液。 </li><li>把10μl的混合溶液中的96孔PCR板各孔中。 </li></ol> 2，拆卸人类胚胎干细胞的分离纯化流式细胞仪<ol><li>从60毫米培养皿用1ml的Accutase 20分钟，在37℃，这是中和人ES介质分离OCT4 :: EGFP的胚胎干细胞系。 </li><li>制备的细胞群体在1ml的FACS缓冲液和细胞调整至1×10 6细胞/ ml。 </li><li>通过一个35微米的细胞过滤帽筒通过细胞样本。 </li><li>细胞分选之前存储管冰。 </li></ol>的FACS纯化的单细胞在96孔平板的每个孔3。裂解<ol><li>排序的样品用于在细胞分选器与受过训练的操作者的EGFP阳性细胞。把单细胞成单细胞Lysis/DNase1解决方案在96孔PCR板。如果有必要，96孔板与样本可以被存储在一个-80℃的冰柜少于一个月。 </li><li>孵育样品5分钟，在室温下细胞裂解。 </li><li>加入1μl终止液终止反应溶解。 </li><li>孵育2分钟，在室温。 </li></ol> 4，反转录<ol><li>添加到20μm的SMA-T15，SMA-A中的每个0.5微升等分。 </li><li>加4μl的5X缓冲液，2微升DTT，1μl的逆转录酶，和1μl的dNTP各孔中。 </li><li>在热循环仪中进行反转录。 <ol><li>在42℃下将热节目×90分钟，灭活逆转录酶在85℃×5分钟。 </li></ol></li></ol> 5，扩增<ol><li>加入4微升ExoSAP-IT试剂到每个反转录样品。 <ol><li>孵育的样品在37℃下15分钟，80℃15分钟以灭活ExoSAP-IT试剂。 </li></ol></li><li>准备PCR反应混合物瓦特第i个SMA-P2（2纳米） </li><li>加入10μlPCR反应混合物中各逆转录样品。 </li><li>进行放大，由20个循环（94℃，30秒），退火（57℃，30秒），延伸（68℃，10分钟）。 </li></ol> 6，实时定量RT-PCR检测性能<ol><li>加10μl的2倍的SYBR Green PCR主要混合液，1微升扩增的cDNA，2 nM的引物，和7微升水的每个孔中。 <ol><li>设置程序随后95℃3秒，60℃30秒×40个循环。 </li></ol></li><li>执行一式两份的技术错误。 </li></ol>

<ol>
	<li>Miyanari, Y., Torres-Padilla, M. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Control+of+ground-state+pluripotency+by+allelic+regulation+of+Nanog.">Control of ground-state pluripotency by allelic regulation of Nanog.</a> Nature. 483, 470-473 (2012).</li><li>Leitch, H. G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Embryonic+germ+cells+from+mice+and+rats+exhibit+properties+consistent+with+a+generic+pluripotent+ground+state.">Embryonic germ cells from mice and rats exhibit properties consistent with a generic pluripotent ground state.</a> Development. 137, 2279-2287 (2010).</li><li>Ramskold, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Full-length+mRNA-Seq+from+single-cell+levels+of+RNA+and+individual+circulating+tumor+cells.">Full-length mRNA-Seq from single-cell levels of RNA and individual circulating tumor cells.</a> Nat Biotechnol. 30, 777-782 (2012).</li><li>Stewart, M. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Clonal+isolation+of+hESCs+reveals+heterogeneity+within+the+pluripotent+stem+cell+compartment.">Clonal isolation of hESCs reveals heterogeneity within the pluripotent stem cell compartment.</a> Nat Methods. 3, 807-815 (2006).</li><li>O'Malley, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-resolution+analysis+with+novel+cell-surface+markers+identifies+routes+to+iPS+cells.">High-resolution analysis with novel cell-surface markers identifies routes to iPS cells.</a> Nature. 499, 88-91 (2013).</li><li>Nichols, J., Smith, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Naive+and+primed+pluripotent+states.">Naive and primed pluripotent states.</a> Cell Stem Cell. 4, 487-492 (2009).</li><li>Kim, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=miR-371-3+expression+predicts+neural+differentiation+propensity+in+human+pluripotent+stem+cells.">miR-371-3 expression predicts neural differentiation propensity in human pluripotent stem cells.</a> Cell Stem Cell. 8, 695-706 (2011).</li><li>Mortazavi, A., Williams, B. A., Mccue, K., Schaeffer, L., Wold, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mapping+and+quantifying+mammalian+transcriptomes+by+RNA-Seq.">Mapping and quantifying mammalian transcriptomes by RNA-Seq.</a> Nat Methods. 5, 621-628 (2008).</li><li>Pan, Q., Shai, O., Lee, L. J., Frey, J., Blencowe, B. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Deep+surveying+of+alternative+splicing+complexity+in+the+human+transcriptome+by+high-throughput+sequencing.">Deep surveying of alternative splicing complexity in the human transcriptome by high-throughput sequencing.</a> Nat Genet. 40, 1413-1415 (2008).</li><li>Wang, E. T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Alternative+isoform+regulation+in+human+tissue+transcriptomes.">Alternative isoform regulation in human tissue transcriptomes.</a> Nature. 456, 470-476 (2008).</li><li>Hockemeyer, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetic+engineering+of+human+pluripotent+cells+using+TALE+nucleases.">Genetic engineering of human pluripotent cells using TALE nucleases.</a> Nat Biotechnol. 29, 731-734 (2011).</li><li>Lee, G., Chambers, S. M., Tomishima, M. J., Studer, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Derivation+of+neural+crest+cells+from+human+pluripotent+stem+cells.">Derivation of neural crest cells from human pluripotent stem cells.</a> Nat Protoc. 5, 688-701 (2010).</li><li>Zhu, Y. Y., Machleder, E. M., Chenchik, A., Li, R., Siebert, P. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reverse+transcriptase+template+switching:+A+SMART+(TM)+approach+for+full-length+cDNA+library+construction.">Reverse transcriptase template switching: A SMART (TM) approach for full-length cDNA library construction.</a> Biotechniques. 30, 892-897 (2001).</li><li>Pan, X. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Two+methods+for+full-length+RNA+sequencing+for+low+quantities+of+cells+and+single+cells.">Two methods for full-length RNA sequencing for low quantities of cells and single cells.</a> P Natl Acad Sci USA. 110, 594-599 (2013).</li><li>Tang, F. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=RNA-Seq+analysis+to+capture+the+transcriptome+landscape+of+a+single+cell.">RNA-Seq analysis to capture the transcriptome landscape of a single cell.</a> Nat Protoc. 5, 516-535 (2010).</li></ol>

作者什么都没有透露。

单细胞基因分析可能是一个主要的工具来预测一个单细胞的功能或整个人口。由于技术的限制，全基因谱分析已经被限制人口的平均水平。中的基因表达模式和个体的细胞和亚群之间的水平的变化已经被提出来引起错误的解释。这些不同的细胞方面可以在人类胚胎干细胞被发现和他们的异质性造成微妙的不同能力维持多能性和命运规范的过程。 我们开发并验证了单细胞定量RT...

大多数高等真核生物的人群是异质从而汇集与人口分析，它往往是难以解释其细胞的功能。在一个人口单个细胞可能是细微的差别，而这些差别能有重要影响整个人群1，2的特性和功能。特别是，人胚胎干细胞（胚胎干细胞）被称为是异质的，这会导致不同程度的多能性和多样化的电位，以微妙独特的方式3，4谱系规范。例如，不同的细胞表面抗原，可用于分类的未分化的多能干细胞，5和奥斯汀史密斯组建议在小鼠胚胎干细胞不同级别的多能性，根据其形态，分化倾向和信号转导通路6的依赖性。这种现象被推测在人类胚胎NIC干细胞7。而整体的研究，不同的干细胞系，而不是单个单个干细胞中进行的，它可能是非常有趣的，分析不同层次的多能性的在单细胞水平，这可能会影响其分化能力，向全体细胞谱系。 细胞和分子异质性可以通过转录分析来决定的，这就是所谓的“单细胞转录组”，并强调定量基因表达水平8-10新方法。用于在单个细胞的基因表达水平的分析，我们开发了单细胞定量RT-PCR的一个简单的，但健壮的协议。我们证实了我们的协议的有效性和可行性通过比较单个细胞裂解物各一半以及人类胚胎干细胞的连续稀释的总RNA，产生最小的技术的变化和差异。进一步，我们使用了遗传记者线隔离同质population利用基因打靶系统的人类胚胎干细胞。用于靶向OCT4基因座（OCT4-2A-EGFP-PGK-迪普 ​​罗构造）和一对TALEN质粒的供体载体被用来11。供体载体和一对TALEN质粒导入人类胚胎干细胞（H9，WA09）使用我们的核转染和克隆选择协议和维护人类胚胎干细胞是基于我们的日常协议12进行的。我们证实了这OCT4基因记者一行表达绿色荧光蛋白的表达OCT4 :: EGFP的胚胎干细胞。 我们的结果表明，个体的胚胎干细胞（排序OCT4 :: EGFP强阳性细胞）保持高水平的OCT4的表达，但不同层次的NANOG的表达。所以，我们的单细胞基因表达分析应该对学习多能干细胞的人口异质性是有用的。

<table border="0" cellpadding="0" cellspacing="0" width="807">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">96 wll PCR Plate</td>
			<td style="width:123px;">USA scientific</td>
			<td style="width:119px;">1402-8900</td>
			<td style="width:311px;"></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:255px;">Ambion Cell Lysis Kit</td>
			<td style="width:123px;">Life Technologies</td>
			<td align="right" style="width:119px;">4458235</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">SMARTScribe Reverse Transcriptase</td>
			<td style="width:123px;">Clonetech</td>
			<td align="right" style="width:119px;">639536</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">ExoSAP-IT</td>
			<td style="width:123px;">USB</td>
			<td align="right" style="width:119px;">78200</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:255px;">Platinum Taq DNA polymerase High Fidelity</td>
			<td style="width:123px;">Invitrogen</td>
			<td align="right" style="width:119px;">11304</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">10mM dNTP Mix, PCR Grade</td>
			<td style="width:123px;">Invitrogen</td>
			<td align="right" style="width:119px;">18427</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">SYBR Universal 2X Master Mix</td>
			<td style="width:123px;">Kapa biosystem</td>
			<td style="width:119px;">KR0389</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Accutase</td>
			<td>Innovative Cell Tech</td>
			<td>S-1100-1</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">FACS buffer</td>
			<td style="width:123px;"></td>
			<td style="width:119px;"></td>
			<td>45 ml PBS, 5 ml a-MEM, 100 ul DNase, filter sterilized</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">35 &#956;m cell strainer cap tubes</td>
			<td style="width:123px;">BD Biosciences</td>
			<td align="right" style="width:119px;">352235</td>
			<td></td>
		</tr>
	</tbody>
</table>

profiling individual human embryonic stem cells by quantitative rt-pcr

干细胞群的异质性阻碍了干细胞生物学的详细了解，如他们的分化倾向朝着不同的谱系。单细胞转录组分析可以为解剖的个体差异的新方法。我们已经开发了单细胞定量RT-PCR法，并证实了该方法在几个基因表达谱效果很好。在单细胞水平上，每一个人类胚胎干细胞，按OCT4 :: EGFP阳性细胞，具有较高的表达OCT4，但不同级别NANOG的表达。我们的单细胞基因表达分析应该是有用的审问人口异质性。

高效率和强大的单细胞RNA扩增 为了尽量减少人类胚胎干细胞中的转录变化，我们使用的OCT4 :: EGFP的胚胎干细胞克隆流式细胞仪净化。 OCT4 :: EGFP阳性细胞分选入96孔板后，每个小区被裂解在裂解缓冲液中，并用SMA-T15（GACATGTATCCGGATGTTTTTTTTTTTTTTTT）引物和具有SMA-A（ACATGTATCCGGATGTGGG锚固转换的poly（A）+ RNA到cDNA全长）通过使用智能模板切换技术。多余的寡核苷酸?...

Watch this Scientific Journal Video about Profiling Individual Human Embryonic Stem Cells by Quantitative RT-PCR at JoVE.com

Profiling Individual Human Embryonic Stem Cells by Quantitative RT-PCR

单细胞基因表达分析是需要了解干细胞的异质性。

分析单个人类胚胎干细胞通过定量RT-PCR

Heterogeneity of stem cell population hampers detailed understanding of stem cell biology, such as their differentiation propensity toward different ...

profiling-individual-human-embryonic-stem-cells-by-quantitative-rt-pcr

Research

JoVE Journal

Biology

11.4K 次观看.  Johns Hopkins University School of Medicine. 单细胞基因表达分析是需要了解干细胞的异质性。 

视频: Profiling Individual Human Embryonic Stem Cells by Quantitative RT-PCR

Propagation of Human Embryonic Stem (ES) Cells

Propagation of Human Embryonic Stem ES Cells

Yeah, so I'm Lauren Deon. I'm in charge of the Human Amgen stem cell co facility at MGH. Yeah, so I'm Lauren, I'm in charge of the Human AM stem cell co facility at MGH.So I've been working with human Amgen stem cells for years now since I was a postdoc in George De Lab before, from four, four years. And so right now we have two cell lines, H one and H nine, which are both from Y cell. And so the way we are expanding or maintaining these cells in culture is by, at least the way we are splitting these cells is by using collagenous.So what I usually do is for the first few passage after throwing the cells, I use a technical, the picking colonies. So in this case, I can check under the microscope which colonies are good and differentiate and nice shape, and I will collect only these colonies and I will cut them in few pieces and put them back in, in a fresh flat. And the, the colonies that look kind of differentiate it are just left them alone.The other way to pass the cells is by using trypsin. So I don't use this technique here. I think collagenase is a little bit safer because human being stem cells don't like to be individualized or they don't like to be alone.So if you do trypsin, if you use trypsin for a little bit too long, if you use it for like three to four minutes, which is the way we use strips in for other type of cells, human stem cells will be individualized and most of them will die or just differentiate or will not attach to the myth. So the idea is you have to keep the cells as clumps. You don't want them to be alone in the in, in the flask.So using collagenase, the advantage is to keep cells as plants. Using chipsy, you just select for cells that will survive this very, very harsh process of g opsonization. So these cells are usually very highly proliferative.So you get, you can adapt your cells to this tripsin process. The problem is that you have cells that they behave differently, they go much faster. And one risk is that you can get some commercial abnormality to, to this, to this very high division process.So you say that ization can cause selection of cells in culture for most proliferative cells.Right. More ative and probably also higher survival rates than other cells. So after proliferation, basically culture after proliferation in tripsin, after several passages become a different culture, these different properties.So it's, it's hard to figure out if they are exactly identical. If you do the test, the usual test, let's say you check markers, regular markers of end differentiated cells like OC four, nano one 60 SC four C, C3, all this molecule might still be expressed. If you do TER formation, this cells might still differentiate and be formed like al like normal cells.If you look at the karyotype, you might have some abnormality, but you might still have a normal karyotype. The, the, the selective advantage might be due to just a mutation that you cannot see by doing a karyotype. So the fact that they grow much faster is by itself I think a little bit worser.And if we want to use these cells for transplantation at some point, I would definitely not use this type of cells.Okay. So would you like to tell me what are the main technical problems with using this technique for, for passages of cells? So using S, yes.It's just a little bit longer and also it's, since the cells are not going as fast, it's just much longer to get a high number of cells to do some experiment. So it's just less convenient I would say. Would you like to tell me about few words about the goals of your experiment?How do you use CS cells? Okay, so my main project here is to get endothelial cells from human AB stem cells. And the idea is to be able to make blood.And we are working a lot with tissue bioengineering labs and one of their goal is to make tissue in vitro. But one of the limitation to this is the lack of blood vessels going through this tissues. So if we can bring endothelial cells or put endothelial cells in this tissue, we would have better growth of this tissue.So the idea few sources of cells are known for endothelial cells like cold blood or pressure blood, but it would be interesting to have another source of cells like human years. And the advantage is since human years can be expanded and most infinitely, you could modify these cells, make some inducible system and be able to use it. Then in your final product, your material cells, in this case.

人类胚胎干细胞（ES细胞）的繁殖

科研

生物学

Derivation of Hematopoietic Stem Cells from Murine Embryonic Stem Cells

A stem cell is defined as a cell with the capacity to both self-renew and generate multiple differentiated progeny.  Embryonic stem cells (ESC) are derived from the blastocyst of the early embryo and are pluripotent in differentiative ability.  Their vast differentiative potential has made them the focus of much research centered on deducing how to coax them to generate clinically useful cell types.  The successful derivation of hematopoietic stem cells (HSC) from mouse ESC has recently been accomplished and can be visualized in this video protocol.  HSC, arguably the most clinically exploited cell population, are used to treat a myriad of hematopoietic malignancies and disorders.  However, many patients that might benefit from HSC therapy lack access to suitable donors.  ESC could provide an alternative source of HSC for these patients.  The following protocol establishes a baseline from which ESC-HSC can be studied and inform efforts to isolate HSC from human ESC.  In this protocol, ESC are differentiated as embryoid bodies (EBs) for 6 days in commercially available serum pre-screened for optimal hematopoietic differentiation.  EBs are then dissociated and infected with retroviral HoxB4.  Infected EB-derived cells are plated on OP9 stroma, a bone marrow stromal cell line derived from the calvaria of  M-CSF-/- mice, and co-cultured in the presence of hematopoiesis promoting cytokines for ten days.  During this co-culture, the infected cells expand greatly, resulting in the generation a heterogeneous pool of 100s of millions of cells.  These cells can then be used to rescue and reconstitute lethally irradiated mice.

This protocol details the derivation of transplantable hematopoietic stem cells from mouse embryonic stem cells (ESC) and their subsequent injection into lethally irradiated recipient mice. Briefly, ESC are differentiated as embryoid bodies, which are then infected with retroviral HoxB4 and co-cultured with OP9 stromal cells and hematopoietic cytokines.

从小鼠胚胎干细胞的造血干细胞的推导

A stem cell is defined as a cell with the capacity to both self-renew and generate multiple differentiated progeny.  Embryonic stem cells (ESC) are ...

Derivation of Human Embryonic Stem Cells by Immunosurgery

The ability of human embryonic stem cells to self-renew and differentiate into all cell types of 
the body suggests that they hold great promise for both medical applications and as a research 
tool for addressing fundamental questions in development and disease. Here, we provide a 
concise, step-by-step protocol for the derivation of human embryonic stem cells from embryos 
by immunosurgical isolation of the inner cell mass. 


The ability of human embryonic stem cells to self-renew and differentiate into all cell types of 
the body suggests that they hold great promise for both medical applications and as a research 
tool for addressing fundamental questions in development and disease. Here, we provide a 
concise, step-by-step protocol for the derivation of human embryonic stem cells from embryos 
by immunosurgical isolation of the inner cell mass.

人类胚胎干细胞的推导Immunosurgery

The ability of human embryonic stem cells to self-renew and differentiate into all cell types of 
the body suggests that they hold great promise for both ...

Probing for Mitochondrial Complex Activity in Human Embryonic Stem Cells

Mitochondria are cytoplasmic organelles that have a primary role in cellular metabolism and homeostasis, regulation of the cell signaling network, and programmed cell death. Mitochondria produce ATP, regulate the cytoplasmic redox state and Ca2+ balance, catabolize fatty acids, synthesize heme, nucleotides, steroid hormones, amino acids, and help assemble iron-sulfur clusters in proteins. Mitochondria also have an essential role in heat production. Mutations of the mitochondrial genome cause several types of human disorder. The accumulation of mtDNA mutations correlates with aging and is suspected to have an important role in the development of cancer. Due to their vitally important role in all cell types, the function of mitochondria must also be critical for stem cells. Key advances have been made in our understanding of stem cell viability, proliferation, and differentiation capacity. But the functional activity of stem cells, in particular their energy status, was not yet been studied in detail. Almost nothing is known about the mitochondrial properties of human embryonic stem cells (hESCs) and their differentiated precursor progeny. One way to understand and evaluate the role of mitochondria in hESC function and developmental potential is to directly measure the activity of mitochondrial respiratory complexes. Here, we describe high resolution clear native gel electrophoresis and subsequent in gel activity visualization as a method for analyzing the five respiratory chain complexes of hESCs.

In this video, we will show you how the mitochondrial respiratory chain complexes of human embryonic stem cells can be analyzed using in gel activity assays.

在人类胚胎干细胞的线粒体复杂的活动初探

Mitochondria are cytoplasmic organelles that have a primary role in cellular metabolism and homeostasis, regulation of the cell signaling network, and ...

Chromatin Immunoprecipitation from Human Embryonic Stem Cells

The functional and structural complexity of the myriad of cells in metazoan organisms arises from a small number of stem cells. Stem cells are characterized by two fundamental properties: self-renewal and multipotency that allows a stem cell to differentiate into virtually any cell type 1. The progression stem cell to differentiated cell is characterized by loss of multipotency, structural and morphological changes and the hierarchic activity of transcription factors and signaling molecules, whose activities establish and maintain cell-type specific gene expression patterns. At the molecular level, cell differentiation involves dynamic changes of the structure and composition of chromatin and the detection of those dynamic changes can provide valuable insights into the functional features of stem cells and the cell differentiation process 2,3. Chromatin is a highly compacted DNA-protein complex that forms when cells package chromosomal DNA with proteins, mainly histones 4. Stemcellness and cell differentiation has been correlated with the presence of specific arrays of regulatory proteins such as epigenetic factors, histone variants, and transcription factors 2,3,5.
 Chromatin immunoprecipitation (ChIP) provides a valuable method to monitor the presence of RNA, proteins, and protein modifications in chromatin 6,7. The comparison of chromatin from different cell types can elucidate dynamic changes in protein-chromatin associations that occur during cell differentiation.
Chromatin immunoprecipitation involves the purification of in vivo cross-linked chromatin. The isolated chromatin is reduced to smaller fragments by enzymatic digestion or mechanical force. Chromatin fragments are precipitated using specific antibodies to target proteins or protein and DNA modifications. The precipitated DNA or RNA is purified and used as a template for PCR or DNA microarray based assays. Prerequisites for a successful ChIP are high quality antibodies to the desired antigen and the availability of chromatin from control cells that do not express the target molecule. ChIP can correlate the presence of proteins, protein and RNA modifications, and RNA with specific target DNA, and depending on the choice of outread tool, detects the association of target molecules at specific target genes or in the context of an entire genome. The comparison of the distribution of proteins in the chromatin of differentiating cells can elucidate the dynamic changes of chromatin composition that coincide with the progression of cells along a cell lineage.

The differentiation of ESC coincides with cell-type specific changes in the structure and composition of chromatin. The detection of those changes provides valuable insights into the mechanisms that define stemcellness and cell differentiation. Chromatin immunoprecipitation (ChIP) represents a valuable method to dissect the molecular mechanisms underlying stem cell differentiation.

从人类胚胎干细胞的染色质免疫沉淀

The functional and structural complexity of the myriad of cells in metazoan organisms arises from a small number of stem cells. Stem cells are ...

In vitro Labeling of Human Embryonic Stem Cells for Magnetic Resonance Imaging

Human embryonic stem cells (hESC) have demonstrated the ability to restore the injured myocardium. Magnetic resonance imaging (MRI) has emerged as one of the predominant imaging modalities to assess the restoration of the injured myocardium. Furthermore, ex-vivo labeling agents, such as iron-oxide nanoparticles, have been employed to track and localize the transplanted stem cells. However, this method does not monitor a fundamental cellular biology property regarding the viability of transplanted cells. It has been known that manganese chloride (MnCl2) enters the cells via voltage-gated calcium (Ca2+) channels when the cells are biologically active, and accumulates intracellularly to generate T1 shortening effect. Therefore, we suggest that manganese-guided MRI can be useful to monitor cell viability after the transplantation of hESC into the myocardium.
In this video, we will show how to label hESC with MnCl2 and how those cells can be clearly seen by using MRI in vitro. At the same time, biological activity of Ca2+-channels will be modulated utilizing both Ca2+-channel agonist and antagonist to evaluate concomitant signal changes.

In this video, we are showing how to label human embryonic stem cells (hESC) with manganese chloride (MnCl2) which can enter cells via voltage-gated calcium channels when the cells are biologically active. Additionally, we show the use of MnCl2 as cellular MRI contrast agent to determine the in vitro viability of hESC.

在人类胚胎干细胞体外培养的标签用于磁共振成像

Human embryonic stem cells (hESC) have demonstrated the ability to restore the injured myocardium. Magnetic resonance imaging (MRI) has emerged as one of ...

Culture and Maintenance of Human Embryonic Stem Cells  

Human embryonic stem (hES) cells must be monitored and cared for in order to maintain healthy, undifferentiated cultures. At minimum, the cultures must be  fed  every day by performing a complete medium change to replenish lost nutrients and to keep the cultures free of unwanted differentiation factors. Although a small amount of differentiation is normal and expected in stem cell cultures, the culture should be routinely cleaned up by manually removing, or "picking" differentiated areas. Identifying and removing excess differentiation from hES cell cultures are essential techniques in the maintenance of a healthy population of cells.

Culture and Maintenance of Human Embryonic Stem Cells

This protocol demonstrates how to maintain healthy, undifferentiated human embryonic stem (ES) cells.

文化和维护人类胚胎干细胞

Human embryonic stem (hES) cells must be monitored and cared for in order to maintain healthy, undifferentiated cultures. At minimum, the cultures must be ...

Chromosomal Spread Preparation of Human Embryonic Stem Cells for Karyotyping

Although human embryonic stem cells (hESC) have been shown to present a stable diploid karyotype 1, many studies have reported that depending on culture conditions they become prone to acquire chromosomal anomalies such as addition of whole or parts of chromosomes. Indeed, during long-term culture, karyotypic alterations are observed when enzymatic or chemical dissociation are used 2,3,4, while manual dissection of colonies for passaging retains a stable karyotype 5. Besides, changes in the environment such as the removal of feeder cells also seem to compromise the genetic integrity of hESC 3,6. Once chromosomal alterations could affect cellular physiology, the characterization of the genetic integrity of hESC in vitro is crucial considering hESC as an essential tool in embryogenesis studies and drug testing. Furthermore, for future therapeutic purposes chromosomal changes are a real concern as it is frequently associated to carcinogenesis.
Here we show a simple and useful method to obtain high quality chromosome spreads for subsequent analysis of chromosome set by G-banding, FISH, SKY or CGH techniques 7,8. We recommend checking the chromosomal status routinely with intervals of 5 passages in order to monitor the appearance of translocations and aneuploidies
Priscila Britto and Rafaela Sartore contributed equally to the paper.

Karyotyping is a simple and useful technique widely used for detecting genetic alterations. Here we describe a step by step protocol for chromosome spread preparation of human embryonic stem cells for monitoring the chromosomal status of these cells maintained in culture.

为核型分析人类胚胎干细胞的染色体蔓延制备

Although human embryonic stem cells (hESC) have been shown to present a stable diploid karyotype 1, many studies have reported that depending on culture ...

Freezing and Thawing Human Embryonic Stem Cells

Since James Thomson et al developed a technique in 1998 to isolate and grow hES in culture, freezing cells for later use and thawing and expanding cells from a frozen stock have become important procedures performed in routine hES cell culture. Since hES cells are very sensitive to the stresses of freezing and thawing, special care must taken. Here we demonstrate the proper technique for rapidly thawing hES cells from liquid nitrogen stocks, plating them on mouse embryonic feeder cells, and slowly freezing them for long-term storage.

Since James Thomson et al developed a technique in 1998 to isolate and grow hES in culture, freezing cells for later use and thawing and expanding cells from a frozen stock have become important procedures performed in routine hES cell culture. Since hES cells are very sensitive to the stresses of freezing and thawing, special care must taken. Here we demonstrate the proper technique for rapidly thawing hES cells from liquid nitrogen stocks, plating them on mouse embryonic feeder cells, and slowly freezing them for long-term storage.

人类胚胎干细胞冷冻和解冻

Since James Thomson et al developed a technique in 1998 to isolate and grow hES in culture, freezing cells for later use and thawing and expanding cells ...

Differentiation of Embryonic Stem Cells into Oligodendrocyte Precursors

Oligodendrocytes are the myelinating cells of the central nervous system. For regenerative cell therapy in demyelinating diseases, there is significant interest in deriving a pure population of lineage-committed oligodendrocyte precursor cells (OPCs) for transplantation. OPCs are characterized by the activity of the transcription factor Olig2 and surface expression of a proteoglycan NG2. Using the GFP-Olig2 (G-Olig2) mouse embryonic stem cell (mESC) reporter line, we optimized conditions for the differentiation of mESCs into GFP+Olig2+NG2+ OPCs. In our protocol, we first describe the generation of embryoid bodies (EBs) from mESCs. Second, we describe treatment of mESC-derived EBs with small molecules: (1) retinoic acid (RA) and (2) a sonic hedgehog (Shh) agonist purmorphamine (Pur) under defined culture conditions to direct EB differentiation into the oligodendroglial lineage. By this approach, OPCs can be obtained with high efficiency (&gt;80%) in a time period of 30 days. Cells derived from mESCs in this protocol are phenotypically similar to OPCs derived from primary tissue culture. The mESC-derived OPCs do not show the spiking property described for a subpopulation of brain OPCs in situ. To study this electrophysiological property, we describe the generation of spiking mESC-derived OPCs by ectopically expressing NaV1.2 subunit. The spiking and nonspiking cells obtained from this protocol will help advance functional studies on the two subpopulations of OPCs.

We describe a small molecule-based protocol for differentiation of mouse embryonic stem cells into oligodendrocyte precursor cells (OPCs). This protocol generates Olig2+NG2+ OPCs with high efficiency by 30 days of differentiation. We also describe a method to generate "spiking" OPCs that can fire action potentials.

胚胎干细胞分化成少突胶质前体

Oligodendrocytes are the myelinating cells of the central nervous system. For regenerative cell therapy in demyelinating diseases, there is significant ...