AEC ist ein Fellow des Jane Coffin Childs Memorial Fund for Medical Research und den Merck Research Laboratories. Wir danken D. Egli und C. Cowan für experimentelle Beratung und Diskussion.

<html> Gefrorene menschlichen Embryonen zu humanen embryonalen Stammzellen (hES) Zellen Ableitung verwendet wurden für die Forschung nach einer ordnungsgemäßen Einwilligung Rahmen von Forschungs-Protokolle, die überprüft und durch das Komitee über die Verwendung von menschlichen Probanden und die Forschung an embryonalen Stammzellen Aufsichtsgremium genehmigt an der Harvard University gespendet . Geschrieben untenstehenden Protokoll basiert auf den veröffentlichten Parametern von Cowan et al berichtet wurden. 2004, mit leichten Modifikationen. Embryo Culture Thaw menschlichen Embryonen mit Quinn Advantage Kit auftauen und Kultur in Tropfen von Global-Medium mit 15% Plasmanate bis zur Entwicklung der erweiterten Blastozystenstadium ergänzt. Immunosurgery-basierte Isolierung der inneren Zellmasse Zubereitung: <ol><li> Bereiten Platten für die Entfernung der Zona pellucida und immunosurgery (siehe unten) durch die Einrichtung Tropfen jeder Lösung in 10cm-Platten. Overlay mit Mineralöl, um Verdunstung zu verhindern. Bereiten Sie eine einzelne Zeile pro Embryo für die Ableitung bestimmt. <ul><li> EmbryoMax Saure Tyrodes, verwenden Sie wie es ist. </li><li> hES-Zell-Ableitung Medien: 75% KO-DMEM, 10% KO-Serum Replacement, 10% Plasmanate, 2,5% ES-Zellen getestet fötales Rinderserum (FBS), 2mM Glutamax-I, 1% nicht-essentiellen Aminosäuren, 50 Einheiten / ml Penicillin, 50μg/ml Streptomycin, 0,055 b-Mercaptoethanol, 5ng/ml bFGF. </li><li> Kaninchen Anti-Human-roten Blutkörperchen primärer Antikörper, rekonstituiert nach Herstellerangaben Vorschlag, bei 1:10 mit hES-Zell-Ableitung Medien verdünnt. </li><li> Meerschweinchen-Komplement-Serum, rekonstituiert nach Herstellerangaben Vorschlag, bei 1:10 mit hES-Zell-Ableitung Medien verdünnt. <img src="/files/ftp_upload/old/574_2008_9_18_6/574_Figure-01.png" alt="574_Figure-01" width="600" height="166" /> </li></ul></li><li> Äquilibrieren alle Platten bis 37 ° C in Gewebekultur-Inkubator vor dem Gebrauch. </li><li> Ziehen Sie 50 ul-100 &amp;mgr; Kapillarpipetten (VWR) für den Einsatz bei der Übertragung von Embryonen. Cut endet mit Diamant-Stift und den Einsatz mit dem Mund pipettieren Schlauch mit einem 0,2 um-Filter ausgestattet. </li></ol> Immunosurgery Vorgehen: Notes: <ul><li> In diesem Verfahren werden die Zellen des Trophektoderm durch kurze Exposition gegenüber Antikörpern gegen menschliche Zellen in Tandem mit Komplement-Aktivität gerichtet zerstört. Deshalb arbeitet Protokoll am besten mit qualitativ hochwertigen Embryonen mit intakter Trophektoderm, da nur die strukturelle Integrität der Blastozyste verhindert, dass die ICM aus auch anfällig für die immunologische Reaktion. </li><li> Alle Verfahren unter Verwendung einer Dissektion Umfang mit beheizten Bühne ausgestattet. </li></ul> Steps: <ol><li> Mund ausspülen Pipette für Embryotransfer mit FBS Embryonen aus Zusammenkleben zu verhindern verwendet werden. </li><li> Transfer von Blastozysten Kulturschale zu hES hält Tropfen AT Gericht. </li><li> Begin Verfahren durch die Übertragung von Blastozysten aus hES Tropfen durch Serie von AT Tropfen. In dritter Tropfen, für die Auflösung der Zona pellucida (in der Regel 5-30 Sekunden) zu beobachten. Achten Sie darauf, nicht zu stark zu behandeln oder Embryo Integrität beeinträchtigt werden kann. <img src="/files/ftp_upload/old/574_2008_7_21_2/574_Figure-02.png" alt="574_Figure-02" width="551" height="273" /> </li><li> Transfer Blastozyste durch Reihe von hES-Zell-Ableitung Medien fallen auf abspülen AT. Preloading Pipette mit Medien wird empfohlen, sofort AT Reaktion zu neutralisieren. Blastozysten können hier abgehalten werden, bis alle AT-verarbeitet wurden. </li><li> Transfer Blastozyste durch Reihe von Primär-Antikörper sinkt, so dass in dritter Tropfen für 30 Minuten Inkubation bei 37 ° C in einer Gewebekultur-Inkubator. </li><li> Transfer Blastozyste durch Reihe von hES-Zell-Ableitung Medien fallen auf abspülen primär. </li><li> Transfer Blastozyste durch Serien von Komplement Tropfen, so dass im dritten Drop für die Lyse von Trophektoderm Zellen zu beobachten. Beachten Sie Blastozyste für die ersten 30 Sekunden auf der Bühne für &quot;sprudelnden&quot; von Trophektoderm Zellen, wie sie zu lysieren. Wenn Lyse innerhalb dieses Zeitrahmens zu beobachten ist, halten Gericht über Mikroskoptisch, um die Reaktion bis zur Fertigstellung zu überwachen. Wenn keine Blasenbildung während der ersten 30 Sekunden beobachtet wird, um Inkubator zurück, Überprüfung alle 5 Minuten, bis die meisten der Trophektoderm hat lysiert. Dies kann 5-15 Minuten. Monitor-Reaktion eng mit Reaktionszeit und mögliche Schäden an der inneren Zellmasse zu minimieren. <img src="/files/ftp_upload/old/574_2008_7_21_3/574_Figure-03.png" alt="574_Figure-03" width="571" height="273" /> </li><li> Transfer Blastozyste durch Reihe von hES-Zell-Ableitung Medien fallen auf abwaschen Komplement-Aktivität. </li><li> Mit Glaspipette mit einem Durchmesser, der geringfügig kleiner als der Blastozyste (gezogen von 10 &amp;mgr; l VWR Kapillaren) ist, zeichnen sich die Blastozyste nach oben und unten abzustreifen meisten der lysierten Trophektoderm. g &quot;alt =&quot; 574_Figure-0 &quot;width =&quot; 577 &quot;height =&quot; 270 &quot;/&gt; </li><li> Platte ICM isolieren auf Feeder-Zellen mitotisch inaktivierten Maus-Embryo-Fibroblasten (MEFs). MEFs sollte der Tag vor der Ableitung vorbereitet werden und wechselte zu hES-Zell-Ableitung Medien Tag. 4-und NUNC Gerichte eignen sich gut für erste Schritte der Ableitung. </li><li> Bitte nicht stören Platte für die ersten 1-2 Tage. Danach täglich überprüfen Auswuchs der embryonalen Stammzellen Kolonien (in der Regel, welche innerhalb von 1-2 Wochen). Die Medien sollten in der Hälfte Bände geändert werden jeden zweiten Tag zu Beginn am Tag 3. </li></ol> ES-Zell-Auswuchs und Passagierung Wenn der hES-Zell-Auswuchs hat ca. 0,5 mm oder mehr erreicht, ist es bereit für die Expansion durch mechanische Kommissionierung. <ol><li> Mechanisch verteilen die Hälfte der Auswuchs und Übertragung auf neue Platten mit frischen Feeder. Embryonale Stammzellen Zellklumpen sollte etwa 30-50 Zellen jeder werden. Lassen Sie andere Hälfte der Auswuchs als Back-up für den ersten Durchgang (p1). Der Auswuchs (p0) können aus verschiedenen Zeiten abgeholt werden, da es sich weiterhin ausbreitet. <img src="/files/ftp_upload/old/574_2008_7_21_5/574_Figure-05.png" alt="574_Figure" width="639" height="219" /> </li><li> Sekundäre Kolonien können in ähnlicher Weise verteilt werden und erweitert in größere Kulturschalen bis Passagen 3-5, zu welchem ​​Zeitpunkt die neuen Zelllinien enzymatische Passagieren mit Trypsin angepasst werden kann. Das Serum-Gehalt der Kulturmedien sollte auch schrittweise auf 1% und 0% werden in diesen ersten Passagen reduziert, um ES-Zell-Differenzierung zu minimieren. </li><li> Alle etablierten embryonalen Stammzelllinien sollte durch Einfrieren unten einen Teil der frühen Passagen für zukünftige Erweiterungen angeschüttet werden. </li><li> Darüber hinaus sollte jeder Zelllinie von Karyotyp-Analyse charakterisiert und validiert werden, indem Pluripotenz und Differenzierung in vitro und in vivo. </li></ol>

<ol>
	<li>Cowan, C. A., Klimanskaya, I., McMahon, J., Atienza, J., Whitmyer, J., Zucker, J. P., Wang, S. P., Morton, C. C., McMahon, A. P., Powers, D., Melton, D. A. <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+embryonic+stem-cell+lines+from+human+blastocysts.">Derivation of embryonic stem-cell lines from human blastocysts.</a> N ENGL J MED. 350 (13), 1353-1356 (2004).</li></ol>

The authors have nothing to disclose.

Das Protokoll hier vorgestellten bietet den Forschern eine prägnante, leicht zu folgen Überblick darüber, wie die Ableitung humanen embryonalen Stammzelllinien durch immunosurgical Isolierung der inneren Zellmasse.

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		<div>
		<table border="1">
		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
		<tbody>
		
<tr>
<td>Quinn's Advantage Thaw Kit </td>
<td>&nbsp;</td>
<td>Sage</td>
<td>ART-8016</td>
<td>&nbsp;</td>
<tr>
<td>Global medium</td>
<td>&nbsp;</td>
<td>Life Global</td>
<td>GMGB-050</td>
<td>&nbsp;</td>
<tr>
<td>Plasmanate</td>
<td>&nbsp;</td>
<td>Talecris</td>
<td>61325</td>
<td>&nbsp;</td>
<tr>
<td>EmbryoMax Acidic Tyrodes</td>
<td>&nbsp;</td>
<td>Chemicon/Millipore</td>
<td>MR-004-D</td>
<td>&nbsp;</td>
<tr>
<td>KO-DMEM</td>
<td>&nbsp;</td>
<td>Invitrogen/Gibco</td>
<td>10829-018</td>
<td>&nbsp;</td>
<tr>
<td>KO-Serum Replacement</td>
<td>&nbsp;</td>
<td>Invitrogen/Gibco</td>
<td>10828-028</td>
<td>&nbsp;</td>
<tr>
<td>ES cell-tested fetal bovine serum, Defined</td>
<td>&nbsp;</td>
<td>Hyclone</td>
<td>SH30070.03</td>
<td>&nbsp;</td>
<tr>
<td>Glutamax-I</td>
<td>&nbsp;</td>
<td>Invitrogen/Gibco</td>
<td>35050-079</td>
<td>&nbsp;</td>
<tr>
<td>Non-essential amino acids</td>
<td>&nbsp;</td>
<td>Invitrogen/Gibco</td>
<td>11140-076</td>
<td>&nbsp;</td>
<tr>
<td>Penicillin/Streptomycin</td>
<td>&nbsp;</td>
<td>Invitrogen/Gibco</td>
<td>15070-063</td>
<td>&nbsp;</td>
<tr>
<td>Recombinant human basic fibroblast growth factor</td>
<td>&nbsp;</td>
<td>Invitrogen</td>
<td>13256-029</td>
<td>&nbsp;</td>
<tr>
<td>Beta-mercaptoethanol </td>
<td>&nbsp;</td>
<td>Invitrogen/Gibco</td>
<td>21985-023</td>
<td>&nbsp;</td>
<tr>
<td>Rabbit anti-human red blood cell primary antibody</td>
<td>&nbsp;</td>
<td>Rockland</td>
<td>109-4139</td>
<td>&nbsp;</td>
<tr>
<td>Guinea-pig complement serum</td>
<td>&nbsp;</td>
<td>Sigma</td>
<td>S-1639</td>
<td>&nbsp;</td>
<tr>
<td>Capillary pipettes in 10 microL, 50 microL, 100 microL sizes</td>
<td>&nbsp;</td>
<td>VWR</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Mouth pipettes with tubing</td>
<td>&nbsp;</td>
<td>VWR</td>
<td>&nbsp;</td>
<td>supplied with capillary pipettes from VWR</td>
</tr>
<tr>
<td>0.2 microm Acrodisc syringe filter </td>
<td>&nbsp;</td>
<td>Pall Life Sciences</td>
<td>PN4192</td>
<td>&nbsp;</td>
<tr>
<td>0.5% Trypsin-EDTA</td>
<td>&nbsp;</td>
<td>Invitrogen/Gibco</td>
<td>25300-120</td>
<td>&nbsp;</td>
<tr>
<td>Tissue culture dishes</td>
<td>&nbsp;</td>
<td>VWR</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Tissue culture dishes</td>
<td>&nbsp;</td>
<td>NUNC</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Nikon SMZ1500 dissection scope equipped with Nikon Tokai Hit ThermoPlate warming stage </td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Mouse embryonic fibroblasts (E12.5)</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>		</tbody>
		</table>
		</div>

derivation of human embryonic stem cells by immunosurgery

Die Fähigkeit von humanen embryonalen Stammzellen sich selbst zu erneuern und zu differenzieren sich in alle Zelltypen des Körpers lässt vermuten, dass sie großes Versprechen für medizinische Anwendungen und als Recherche-Tool für die Bewältigung grundlegender Fragen in Entwicklung und Krankheit zu halten. Hier bieten wir Ihnen einen kurzen Schritt-für-Schritt-Protokoll für die Gewinnung menschlicher embryonaler Stammzellen aus Embryonen, die durch immunosurgical Isolierung der inneren Zellmasse.

Watch this Scientific Journal Video about Derivation of Human Embryonic Stem Cells by Immunosurgery at JoVE.com

Derivation of Human Embryonic Stem Cells by Immunosurgery

Gewinnung menschlicher embryonaler Stammzellen durch 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 ...

derivation-of-human-embryonic-stem-cells-by-immunosurgery

Research

JoVE Journal

Biology

33.7K Aufrufe.  Harvard. Die Fähigkeit von humanen embryonalen Stammzellen sich selbst zu erneuern und zu differenzieren sich in alle Zelltypen des Körpers lässt vermuten, dass sie großes Versprechen für medizinische Anwendungen und als Recherche-Tool für die Bewältigung grundlegender Fragen in Entwicklung und Krankheit zu halten. Hier bieten wir Ihnen einen kurzen Schritt-für-Schritt-Protokoll für die Gewinnung menschlicher embryonaler Stammzellen aus Embryonen, die durch immunosurgical...

Serie: Derivation of Human Embryonic Stem Cells by Immunosurgery

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.

Vermehrung von humanen embryonalen Stammzellen (ES-Zellen)

Forschung

Biologie

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.

Ableitung von hämatopoetischen Stammzellen aus embryonalen Stammzellen der Maus

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 ...

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.

Probing für Mitochondriale komplexe Aktivität in humanen embryonalen Stammzellen

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.

Chromatin Immunopräzipitation von humanen embryonalen Stammzellen

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

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.

Kultur und Wartung von humanen embryonalen Stammzellen

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.

Chromosomale Spread-Vorbereitung von humanen embryonalen Stammzellen für die Karyotypisierung

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.

Einfrieren und Auftauen humanen embryonalen Stammzellen

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 ...

Isolation and Derivation of Mouse Embryonic Germinal Cells

The ability of embryonic germinal cells (EG) to differentiate into primordial germinal cells (PGCs) and later into gametes during early developmental stages is a perfect model to address our hypothesis about cancer and infertility. This protocol shows how to isolate primordial germinal cells from developing gonads in 10.5-11.5 days post coitum (dpc) mouse embryos.  Developing gonadal ridges from mouse embryos (C57BL6J) were dissociated by mechanical disruption with collagenase, then plated in a mouse embryo fibroblast feeder layer (MEF-CF1) that was previously mitotically inactivated with mitomycin C in the presence of knockout media and supplemented with Leukemia Inhibitor Factor (LIF), basic Fibroblast Growth Factor (bFGF), and Stem Cell Factor (SCF).  Using these optimized methods for PCG identification, isolation, and establishment of culture conditions permits long term cultures of EG cells for more than 40 days.  The embryonic germinal cell lines showed embryonic phenotype and expression of common used markers of the pluripotent state.  Isolation and derivation of germinal cells in culture provide a tool to understand their development in vitro and offer the opportunity to monitor cumulative damage at genetic and epigenetic levels after exposure to oxidative stress.

The ability of embryonic germinal cells to differentiate into primordial germinal cells during early development stages is a perfect model to address our hypothesis about cancer and infertility. This protocol shows how to isolate primordial germinal cells from developing gonads in 10.5-11.5 days post coitum mouse embryos.

Isolation und Ableitung von embryonalen Maus-Keimzellen

The ability of embryonic germinal cells (EG) to differentiate into primordial germinal cells (PGCs) and later into gametes during early developmental ...

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.

Differenzierung von embryonalen Stammzellen in Oligodendrozyten Precursors

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

Derivation of Mouse Trophoblast Stem Cells from Blastocysts

Specification of the trophectoderm is one of the earliest differentiation events of mammalian development. The trophoblast lineage derived from the trophectoderm mediates implantation and generates the fetal part of the placenta. As a result, the development of this lineage is essential for embryo survival. Derivation of trophoblast stem (TS) cells from mouse blastocysts was first described by Tanaka et al. 1998. The ability of TS cells to preserve the trophoblast specific property and their expression of stage- and cell type-specific markers after proper stimulation provides a valuable model system to investigate trophoblast lineage development whereby recapitulating early placentation events. Furthermore, trophoblast cells are one of the few somatic cell types undergoing natural genome amplification. Although the molecular pathways underlying trophoblast polyploidization have begun to unravel, the physiological role and advantage of trophoblast genome amplification remains largely elusive. The development of diploid stem cells into polyploid trophoblast cells in culture makes this ex vivo system an excellent tool for elucidating the regulatory mechanism of genome replication and instability in health and disease. Here we describe a protocol based on previous reports with modification published in Chiu et al. 2008.

In this video, we demonstrate the isolation of mouse blastocysts and the derivation of trophoblast stem cells from blastocysts. We also describe conditions for maintenance of the stem cell property as well as induction of differentiation in culture.

Ableitung der Maus Trophoblast Stammzellen aus Blastozysten

Specification of the trophectoderm is one of the earliest differentiation events of mammalian development. The trophoblast lineage derived from the ...