The skillful technical assistance of Jasmin Kresse is gratefully acknowledged.

1. Differentiation of Human ESC towards the Definitive Endoderm
<ol>
	<li>Cultivate human embryonic stem cells (ESCs) in an incubator at 37 &#176;C and 5% CO2.</li>
	<li>Coat a new 6-well cell culture plate with 1 ml of a basement membrane matrix and incubate the culture-ware for at least 30 min at RT. For specific details please turn to the respective manufacturer&#39;s instructions.</li>
	<li>Confirm that the cultured human ESCs have reached 80%-90% confluency under the microscope using a low magnification...

<ol>
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M., Lenzen, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Insulin-producing+surrogate+beta-cells+from+embryonic+stem+cells:+are+we+there+yet.">Insulin-producing surrogate beta-cells from embryonic stem cells: are we there yet.</a> Mol Ther. 19 (10), 1759-1768 (2011).</li><li>Katsirntaki, K., 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=Bronchoalveolar+sublineage+specification+of+pluripotent+stem+cells:+effect+of+dexamethasone+plus+cAMP-elevating+agents+and+keratinocyte+growth+factor.">Bronchoalveolar sublineage specification of pluripotent stem cells: effect of dexamethasone plus cAMP-elevating agents and keratinocyte growth factor.</a> Tissue Eng Part A. 21 (3-4), 669-682 (2015).</li><li>Abranches, E., 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=Neural+differentiation+of+embryonic+stem+cells+in+vitro:+a+road+map+to+neurogenesis+in+the+embryo.">Neural differentiation of embryonic stem cells in vitro: a road map to neurogenesis in the embryo.</a> PLoS One. 4 (7), e6286 (2009).</li><li>Naujok, O., Diekmann, U., Lenzen, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+generation+of+definitive+endoderm+from+human+embryonic+stem+cells+is+initially+independent+from+activin+A+but+requires+canonical+Wnt-signaling.">The generation of definitive endoderm from human embryonic stem cells is initially independent from activin A but requires canonical Wnt-signaling.</a> Stem Cell Rev. 10 (4), 480-493 (2014).</li><li>D'Amour, K. A., 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=Production+of+pancreatic+hormone-expressing+endocrine+cells+from+human+embryonic+stem+cells.">Production of pancreatic hormone-expressing endocrine cells from human embryonic stem cells.</a> Nat Biotechnol. 24 (11), 1392-1401 (2006).</li><li>Diekmann, U., Lenzen, S., Naujok, O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+reliable+and+efficient+protocol+for+human+pluripotent+stem+cell+differentiation+into+the+definitive+endoderm+based+on+dispersed+single+cells.">A reliable and efficient protocol for human pluripotent stem cell differentiation into the definitive endoderm based on dispersed single cells.</a> Stem Cells Dev. 24 (2), 190-204 (2015).</li><li>Kim, P. T., Ong, C. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differentiation+of+definitive+endoderm+from+mouse+embryonic+stem+cells.">Differentiation of definitive endoderm from mouse embryonic stem cells.</a> Results Probl Cell Differ. 55, 303-319 (2012).</li><li>Katoh, M., Katoh, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Integrative+genomic+analyses+of+CXCR4:+transcriptional+regulation+of+CXCR4+based+on+TGFbeta,+Nodal,+Activin+signaling+and+POU5F1,+FOXA2,+FOXC2,+FOXH1,+SOX17,+and+GFI1+transcription+factors.">Integrative genomic analyses of CXCR4: transcriptional regulation of CXCR4 based on TGFbeta, Nodal, Activin signaling and POU5F1, FOXA2, FOXC2, FOXH1, SOX17, and GFI1 transcription factors.</a> Int J Oncol. 36 (2), 415-420 (2010).</li><li>Nostro, M. 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=Stage-specific+signaling+through+TGFbeta+family+members+and+WNT+regulates+patterning+and+pancreatic+specification+of+human+pluripotent+stem+cells.">Stage-specific signaling through TGFbeta family members and WNT regulates patterning and pancreatic specification of human pluripotent stem cells.</a> Development. 138 (5), 861-871 (2011).</li><li>Rezania, A., 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=Maturation+of+human+embryonic+stem+cell-derived+pancreatic+progenitors+into+functional+islets+capable+of+treating+pre-existing+diabetes+in+mice.">Maturation of human embryonic stem cell-derived pancreatic progenitors into functional islets capable of treating pre-existing diabetes in mice.</a> Diabetes. 61 (8), 2016-2029 (2012).</li><li>Bruin, J. E., 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=Maturation+and+function+of+human+embryonic+stem+cell-derived+pancreatic+progenitors+in+macroencapsulation+devices+following+transplant+into+mice.">Maturation and function of human embryonic stem cell-derived pancreatic progenitors in macroencapsulation devices following transplant into mice.</a> Diabetologia. 56 (9), 1987-1998 (2013).</li><li>Fu, W., Wang, S. J., Zhou, G. D., Liu, W., Cao, Y., Zhang, W. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Residual+undifferentiated+cells+during+differentiation+of+induced+pluripotent+stem+cells+in+vitro+and+in+vivo.">Residual undifferentiated cells during differentiation of induced pluripotent stem cells in vitro and in vivo.</a> Stem Cells Dev. 21 (4), 521-529 (2012).</li><li>Hentze, H., Soong, P. L., Wang, S. T., Phillips, B. W., Putti, T. C., Dunn, N. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Teratoma+formation+by+human+embryonic+stem+cells:+evaluation+of+essential+parameters+for+future+safety+studies.">Teratoma formation by human embryonic stem cells: evaluation of essential parameters for future safety studies.</a> Stem Cell Res. 2 (3), 198-210 (2009).</li><li>Herberts, C. A., Kwa, M. S., Hermsen, H. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Risk+factors+in+the+development+of+stem+cell+therapy.">Risk factors in the development of stem cell therapy.</a> J Transl Med. 9, 29 (2011).</li><li>Naujok, O., Kaldrack, J., Taivankhuu, T., J&#246;rns, A., Lenzen, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Selective+removal+of+undifferentiated+embryonic+stem+cells+from+differentiation+cultures+through+HSV1+thymidine+kinase+and+ganciclovir+treatment.">Selective removal of undifferentiated embryonic stem cells from differentiation cultures through HSV1 thymidine kinase and ganciclovir treatment.</a> Stem Cell Rev. 6 (3), 450-461 (2010).</li><li>Pan, Y., Ouyang, Z., Wong, W. H., Baker, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+new+FACS+approach+isolates+hESC+derived+endoderm+using+transcription+factors.">A new FACS approach isolates hESC derived endoderm using transcription factors.</a> PLoS One. 6 (3), 17536 (2011).</li></ol>

The authors declare that they have no competing financial interests.

Currently used differentiation protocols rarely result in 100% differentiated cells. For reasons that still have to be addressed some cells resist the differentiation process. Depending on the efficiency of the used differentiation protocol and the propensity of the ESC line a certain number of residual pluripotent cells are commonly observed even after differentiation into the definitive endoderm. These residual cells may impair downstream differentiations or further analysis such as transcriptomics, proteomics, and miR...

Pluripotent stem cells such as embryonic stem cells (ESCs) have the capability to differentiate into virtually any cell type of the human body. Thus, in vitro differentiation protocols can be used to generate numerous adult cell types such as cardiomyocytes1, hepatocytes2, beta cells3, lung epithelial4 or neuronal cells5. This makes ESCs a valuable tool for the potential treatment of various degenerative diseases3.
The in vitro differentiation of ESCs towards adult tissues of the lung, liver and pancreas requires a pseudo-gastrulation into cells reminiscent of the definitive endoderm (DE)6. Since downstream differentiation towards the aforementioned somatic cell types is significantly less efficient, an optimal endoderm differentiation is regarded as rate-limiting7. Cells that are committed towards the endoderm lineage undergo characteristic changes in their gene expression profile. Pluripotency master regulator genes are down regulated, whereas the expression of other transcription factors such as FOXA2, SOX17, HNF1B, members of the GATA family and the surface receptor CXCR4 is highly upregulated6, 8, 9. CXCR4 is known to be transactivated by SMAD2/3, downstream of Nodal/TGF-&#946; signaling and SOX17 due to specific binding sites in its promoter region10. Thus it is a very suitable marker used in a number of reports6, 8, 11-13. These expression changes reflects a pseudo-gastrulation event, in which ESCs first acquire characteristics of a primitive streak-like cell population and subsequently commit into the endoderm germ layer6.
However, differentiation protocols are rarely 100% efficient as a few cells may resist the differentiation process or differentiate towards other unintended lineages14. These cells may negatively influence further differentiation. Furthermore, residual undifferentiated cells harbor great risks for later transplantation experiments and may give rise to teratomas15-17.
To remove these unwanted cells early-on the surface marker CXCR4 can be used for the purification of cells that are committed towards the DE18. Here, we describe a method for the positive selection of CXCR4+ cells from DE differentiation cultures. For this, the surface marker CXCR4 is bound by an antibody which then in turn binds to magnetic microbeads. Unlike the harsh conditions during FACS sorting, the magnetically labeled DE-like cells can then easily be purified in a benchtop format using a gentle purification method. This protocol provides a straightforward method for the removal of cell populations that resisted the DE differentiation process.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr >
			<td >Hues8 human embryonic stem cell line</td>
			<td >Harvard Department of stem cell &#38; regenerative biology</td>
			<td >NA</td>
			<td >Suitable cell line for endoderm generation</td>
		</tr>
		<tr >
			<td >Hes3 human embryonic stem cell line</td>
			<td >ES Cell International</td>
			<td >NA</td>
			<td >Suitable and robust cell line for endoderm generation</td>
		</tr>
		<tr >
			<td >mTeSR1</td>
			<td >Stemcell Technologies</td>
			<td >5850</td>
			<td >ESC culture medium</td>
		</tr>
		<tr >
			<td >FCS</td>
			<td >Biowest</td>
			<td >S1860</td>
			<td ></td>
		</tr>
		<tr >
			<td >Advanced RPMI 1640</td>
			<td >Life Technologies</td>
			<td >12633012</td>
			<td ></td>
		</tr>
		<tr >
			<td >CD184 (CXCR4)-APC, human</td>
			<td >Miltenyi Biotec</td>
			<td >130-098-357</td>
			<td ></td>
		</tr>
		<tr >
			<td >anti-APC MicroBeads</td>
			<td >Miltenyi Biotec</td>
			<td >130-090-855&#160;</td>
			<td ></td>
		</tr>
		<tr >
			<td >OctoMACS Separator</td>
			<td >Miltenyi Biotec</td>
			<td >130-042-109</td>
			<td >magnetic field</td>
		</tr>
		<tr >
			<td >Y-27632</td>
			<td >Selleck Chemicals</td>
			<td >S1049</td>
			<td >ROCK inhibitor</td>
		</tr>
		<tr >
			<td >CHIR-99021</td>
			<td >Tocris Bioscience</td>
			<td >4423</td>
			<td ></td>
		</tr>
		<tr >
			<td >Activin A</td>
			<td >Peprotech</td>
			<td >120-14</td>
			<td ></td>
		</tr>
		<tr >
			<td >Gentle Cell Dissociation Reagent</td>
			<td >Stemcell Technologies</td>
			<td >7174</td>
			<td >Enzyme-free passaging solution, alternative: Trypsin/EDTA</td>
		</tr>
		<tr >
			<td >Matrigel*</td>
			<td >Corning</td>
			<td >354277</td>
			<td >basement membrane matrix 
			 * solve and store in aliquots at -80 &#176;C as outlined in the suppliers manual. Upon use, thaw on ice, dilute in 25 ml ice-cold knockout DMEM/F-12. 
Add 1 ml to each well of a 6-well plate and incubate for 45 min at room temperature. 
Remove the matrigel and use immediately.
			</td>
		</tr>
		<tr >
			<td >MS Columns</td>
			<td >Miltenyi Biotec</td>
			<td >30-042-201</td>
			<td ></td>
		</tr>
		<tr >
			<td >MACS Separator</td>
			<td >Miltenyi Biotec</td>
			<td >130-042-302</td>
			<td ></td>
		</tr>
		<tr >
			<td >Human FOXA2 FW gggagcggtgaagatgga</td>
			<td >Life Technologies</td>
			<td >NA</td>
			<td ></td>
		</tr>
		<tr >
			<td >Human FOXA2 REV tcatgttgctcacggaggagta</td>
			<td >Life Technologies</td>
			<td >NA</td>
			<td ></td>
		</tr>
		<tr >
			<td >Human GSC FW gaggagaaagtggaggtctggtt</td>
			<td >Life Technologies</td>
			<td >NA</td>
			<td ></td>
		</tr>
		<tr >
			<td >Human GSC REV ctctgatgaggaccgcttctg</td>
			<td >Life Technologies</td>
			<td >NA</td>
			<td ></td>
		</tr>
		<tr >
			<td >SOX17 TaqMan assay</td>
			<td >Applied Biosystems</td>
			<td >Hs00751752_s1</td>
			<td ></td>
		</tr>
		<tr >
			<td >Human SOX7 FW gatgctgggaaagtcgtggaagg</td>
			<td >Life Technologies</td>
			<td >NA</td>
			<td ></td>
		</tr>
		<tr >
			<td >Human SOX7 REV tgcgcggccggtacttgtag</td>
			<td >Life Technologies</td>
			<td >NA</td>
			<td ></td>
		</tr>
		<tr >
			<td >Human POU5F1 FW cttgctgcagaagtgggtggagg</td>
			<td >Life Technologies</td>
			<td >NA</td>
			<td ></td>
		</tr>
		<tr >
			<td >Human POU5F1 REV ctgcagtgtgggtttcgggca</td>
			<td >Life Technologies</td>
			<td >NA</td>
			<td ></td>
		</tr>
		<tr >
			<td >Human Nanog FW ccgagggcagacatcatcc</td>
			<td >Life Technologies</td>
			<td >NA</td>
			<td ></td>
		</tr>
		<tr >
			<td >Human Nanog REV ccatccactgccacatcttct</td>
			<td >Life Technologies</td>
			<td >NA</td>
			<td ></td>
		</tr>
		<tr >
			<td >Human TBP FW caa cag cct gcc acc tta cgc tc</td>
			<td >Life Technologies</td>
			<td >NA</td>
			<td ></td>
		</tr>
		<tr >
			<td >Human TBP REV agg ctg tgg ggt cag tcc agt g</td>
			<td >Life Technologies</td>
			<td >NA</td>
			<td ></td>
		</tr>
		<tr >
			<td >Human TUBA1A FW ggc agt gtt tgt aga ctt gga acc c</td>
			<td >Life Technologies</td>
			<td >NA</td>
			<td ></td>
		</tr>
		<tr >
			<td >Human TUBA1A REV tgt gat aag ttg ctc agg gtg gaa g</td>
			<td >Life Technologies</td>
			<td >NA</td>
			<td ></td>
		</tr>
		<tr >
			<td >Human G6PD FW agg ccg tca cca aga aca ttc a</td>
			<td >Life Technologies</td>
			<td >NA</td>
			<td ></td>
		</tr>
		<tr >
			<td >Human G6PD REV cga tga tgc ggt tcc agc cta t
</td>
			<td >Life Technologies</td>
			<td >NA</td>
			<td ></td>
		</tr>
		<tr >
			<td >Anti-SOX2</td>
			<td >Santa Cruz Biotechnology</td>
			<td >sc-17320</td>
			<td ></td>
		</tr>
		<tr >
			<td >Anti-FOXA2</td>
			<td >MerckMillipore</td>
			<td >07-633</td>
			<td ></td>
		</tr>
		<tr >
			<td >Anti-SOX17</td>
			<td >R&#38;D Systems</td>
			<td >AF1924</td>
			<td ></td>
		</tr>
	
		<tr >
			<td ></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr >
			<td >NA = not applicable</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

a quick and efficient method for the purification of endoderm cells generated from human embryonic stem cells

The differentiation capabilities of pluripotent stem cells such as embryonic stem cells (ESCs) allow a potential therapeutic application for cell replacement therapies. Terminally differentiated cell types could be used for the treatment of various degenerative diseases. In vitro differentiation of these cells towards tissues of the lung, liver and pancreas requires as a first step the generation of definitive endodermal cells. This step is rate-limiting for further differentiation towards terminally matured cell types such as insulin-producing beta cells, hepatocytes or other endoderm-derived cell types. Cells that are committed towards the endoderm lineage highly express a multitude of transcription factors such as FOXA2, SOX17, HNF1B, members of the GATA family, and the surface receptor CXCR4. However, differentiation protocols are rarely 100% efficient. Here, we describe a method for the purification of a CXCR4+ cell population after differentiation into the DE by using magnetic microbeads. This purification additionally removes cells of unwanted lineages. The gentle purification method is quick and reliable and might be used to improve downstream applications and differentiations.

Upon differentiation ESCs undergo drastic changes in gene and protein expression. Figure 1 depicts typical marker genes that can be used to verify a successful endoderm differentiation. Prime targets for a gene expression analysis are GSC, FOXA2, and SOX17. In a relative gene expression analysis especially FOXA2 and SOX17 are increased by &#62; 2,000 fold when compared to undifferentiated ESCs. GSC is ...

Watch this Scientific Journal Video about A Quick and Efficient Method for the Purification of Endoderm Cells Generated from Human Embryonic Stem Cells at JoVE.com

A Quick and Efficient Method for the Purification of Endoderm Cells Generated from Human Embryonic Stem Cells

Here, we describe a method for the purification of differentiated human embryonic stem cells that are committed towards the definitive endoderm for the improvement of downstream applications and further differentiations.

The differentiation capabilities of pluripotent stem cells such as embryonic stem cells (ESCs) allow a potential therapeutic application for cell ...

The overall goal of this method is to purify endodermal cells generated from human embryonic stem or ES cells. This method can help answer key questions in the stem cell field about endodermal differentiation. The main advantage of this technique is that a pure endoderm cell population can be obtained after the removal of undifferentiated cells.Before beginning the procedure, coat six well cell culture plates with one milliliter of basement membrane matrix per well. For at least 30 minutes at room temperature. Then, to harvest the human ES cells, aspirate the medium from an 80 to 90%confluent human embryonic stem cell culture with a sterile glass Pasture pipette.And wash the cells with two milliliters of PBS per well. Shaking the plate and aspirating the saline to remove the dead cells and debris. Next, gently dissociate the cell clusters with one milliliter of enzyme-free passaging solution reagent, at 37 degrees Celsius and 5%carbon dioxide until the cells exhibit clear signs of disruption into smaller clusters.After about seven minutes, add one milliliter of DMMF12 medium to the wells. And pipette up and down a few times with a one milliliter pipette tip to detach the remaining cell aggregates into a single cell suspension. Using the same pipette, transfer the cells into a centrifugation tube and rinse the wells with one milliliter of fresh DMMF12 medium, pooling the washes in the tube.After spinning down the cells, re-suspend the pellet in five milliliters of ES cell culture medium supplemented with ROCK inhibitor. Count the cells and seed 1.5:4 times 10 to the fifth cells per well on the basement membrane matrix coated plates in culture medium supplemented with ROCK inhibitor to prevent apoptosis. Incubate the cells for approximately 24 hours.And then use a sterile, glass Pasteur pipette to replace the medium in each well with 2 milliliters of primitive streak induction medium. After 24 more hours of culture, replace the medium with endoderm induction medium for a 48 hour incubation with daily medium changes. On the last day of culture and at least one hour before harvesting the cells, add fresh ROCK inhibitor to the culture medium.Then use a sterile, glass Pasteur pipette to aspirate the medium from each of the wells and dissociate the cells with enzyme-free passaging solution reagent as just demonstrated. When a single-cell suspension has been achieved, count the cells and centrifuge them. Make sure that from this point on, all medium and buffers contain the ROCK inhibitor to prevent the cells from dying.Otherwise, they will not be attached properly after receding. Re-suspend the pellet in 100 microliters of PEB buffer, supplemented with ROCK inhibitor per 1 times 10 to the seventh cells. Then add CXCR4 APC antibody to the cells.Gently flicking the tube to mix. After 15 minutes at 4 degrees Celsius, wash the cells in one to two milliliters of PEB buffer and use a sterile, glass Pasteur pipette to aspirate the supernatant. Re-suspend the pellet in 80 microliters of PEB buffer per 1 times 10 to the seventh cells and add 20 microliters of anti-APC microbeads to the cells.Mix the sample with gentle flicking. Then incubate the cells at four degrees Celsius for 15 minutes. At the end of the incubation, wash the cells with one to two milliliters of PEB buffer supplemented with ROCK inhibitor.And re-suspend the pellet in 500 microliters of fresh PEB buffer plus inhibitor. To isolate the CXCR4+cells by magnetic bead separation, load a medium sized magnetic column onto an appropriately sized magnet and pre-rinse the column with 500 microliters PEB buffer plus ROCK inhibitor. When all of the wash has drained from the top of the column, apply the entire magnetic bead labeled cell volume to the column, collecting the flow through in a conical tube.Wash the column with three applications of 500 microliters of PEB buffer plus ROCK inhibitor. Then transfer the column from the magnet into a suitable collection tube. And plunge one milliliter of PEB buffer plus ROCK inhibitor through the column to collect the CXCR4+cells.Optionally, all of the flow through samples can be collected separately and 20 microliter aliquots from each sample can be used to determine the percentage of CXCR4+cells in each alouette by flow cytometry. This procedure can be repeated with the first flow through to collect cells that did not bind to the column. Then pool both allouted CXCR4+samples and centrifuge them.Finally, re-suspend the pellet in one milliliter of endoderm induction medium supplemented with ROCK inhibitor And seed the cells at the appropriate density in a basement membrane matrix coated cell culture container. Prior to their differentiation, human ES cells express high levels of the pluripotency marker SOX2. Whereas, the definitive endoderm marker, FOXA2 is not detected.Upon differentiation, the ES cells undergo drastic changes in their gene and protein expression. Indeed, after four days in differentiation medium, SOX17 and FOXA2 are co-expressed uniformly within the nuclei of many of the former ES cells, a hallmark of definitive endoderm commitment. Some cells resist the differentiation process, expressing neither of the two marker proteins.And in fact, retain their pluripotency marker SOX2 expression. In this representative experiment, on day three of differentiation, nearly 60%of the harvested ES cells expressed CXCR4, the purity of which was enriched to over 85%after magnetic bead sorting of the pluripotent and other unwanted lineage cells. After seeding the purified CXCR4+cells, only a few SOX2+cells are detected, with the majority of the seeded cells expressing FOXA2.Once mastered, this technique can be completed within two hours, if performed properly. Following this procedure, other like immune histochemistry or QPCR can be performed to answer additional questions about the differentiation process. After watching this video, you should have a good understanding of how to purify endoderm cells by magnetic bead sorting.

a-quick-efficient-method-for-purification-endoderm-cells-generated

Research

JoVE Journal

Developmental Biology

8.3K 조회수.  Hannover Medical School. The overall goal of this method is to purify endodermal cells generated from human embryonic stem or ES cells. This method can help answer key questions in the stem cell field about endodermal differentiation. The main advantage of this technique is that a pure endoderm cell population can be obtained after the removal of undifferentiated cells.Before beginning the procedure, coat six well cell culture plates with one milliliter of basement membrane matrix per well. For at least 30 min...