Diese Arbeit von der Human Tissue and Cell Research Foundation, die menschliche Gewebe für die Forschung macht möglich gemacht. Und hepacult GmbH Finanzielle Unterstützung für diese Arbeit wurde vom Bundesministerium für Bildung und Forschung (: Virtual Liver Network, Förderkennzeichen 0315759 Zuschuss Name) erhalten. Unser Dank gilt auch den technischen Assistenten aus dem Klinikum Großhadern Gewebebank für die Sammlung der Leberproben und die technischen Assistenten aus der Zellisolierung Core Facility für die Durchführung der Leberdurchblutung und Hepatozyten Isolation zu gehen. Insbesondere möchten wir Natalja Löwen für den Nachweis dieses Verfahren in dem Video zu danken. Schließlich möchten wir Natalja Löwen und Edeltraud Hanesch für die Erstellung der Illustrationen für Abbildung 1 und die Zahlen in der schematischen Überblick über die Video danken.

1. Vorbereitung der Perfusion und Isolation Lösungen <ol><li> Vorbereitung der für die Durchblutung der Leber Stück und die Isolierung von Hepatozyten nach Tabelle 1 erforderlichen Lösungen. Lösungen bei 4 ° C bis zur Verwendung gelagert werden. </li><li> Sterilfilter alle Lösungen mit einem 0,22 um Filter. </li><li> Alle Lösungen, die in Kontakt mit der Leber kommen sollte steril sein. </li></ol> 2. Vorbereitung der Perfusion Geräte und Lösungen <ol><li> Die Ausrüstung für die Durchblutung der Leber Stück sollte wie in Abbildung 1 gezeigt, eingestellt werden. </li><li> Das Wasserbad sollte bei einer geeigneten Temperatur, die in jedem einzelnen Versuchsaufbau unterschiedlich ist, so eingestellt werden, dass die Lösungen bei der Temperatur von 37 ° C, wenn sie die Leber Stück zu erreichen. In diesem Fall wird das Wasserbad auf 41 ° C eingestellt, um die Lösungen 1, 2 und 3 und die ummantelten Glaskühler wärmen. Lösung 4 sollte erwärmt werden37 ° C in einem separaten Wasserbad für den Verlust von Kollagenase-Aktivität zu reduzieren. </li><li> Kurz vor Leberperfusion, schalten Sie den Regler der Gastank mit 95% O 2/5% CO 2, um die Sauerstoffgerät (1E) Gas. </li></ol> 3. Perfusion der Leber <ol><li> Eine Leberstück mit so viel Glisson-Kapsel intakt wie möglich und im Idealfall mit nur 1 Schnittfläche sollte von einem Pathologen zur Perfusion erzielt werden. </li><li> Legen Sie diese Leber Stück auf der Büchner-Trichter, die einen perforierten Filterscheibe (Abbildung 1B) enthält. </li><li> Die Perfusion System sollte mit der Lösung 1 grundiert werden. </li><li> Mit einer niedrigen Flussrate sollte gekrümmte Bewässerung Kanülen mit Oliven-Tipps in die größeren Blutgefäße auf der Schnittfläche der Leber Stück eingesetzt werden. Wie Blut spült aus der Leber wird das Gewebe leichter in Gebieten mit guter Durchblutung. Die Anzahl der Kanülen für verschiedene Größen verwendetder Leber ist in 2A gezeigt. Die Spurgröße gewählt werden sollte in einer Passform, die die Kanülen in Position zu halten die Folge. Die kleineren Blutgefäßen sollte für die Perfusion Puffer aus der Leber Stück abtropfen offen gelassen werden. </li><li> Erhöhung der Strömungsgeschwindigkeit an der peristaltischen Pumpe zwischen 110 bis 460 ml / min in Abhängigkeit von der Größe der Leber (Fig. 2B). Dies führt zu einer mittleren Strömungsrate von 44 ± 16 ml / min pro Kanüle (Fig. 2C). Die gewählte Geschwindigkeit hängt von der Leber Stück und sollte in einem leichten Hyalurosmooth Stück der Leber führen. In einigen Fällen kann es notwendig sein, zu klemmen herunter einige der offene Behälter mit Mikrogefäßklemmen, die oben erwähnte leichte Aufpolsterung erzielen. Eine gute Durchblutung beobachtet werden kann, wenn die Leber Stück ist eine hellere Farbe ganz. </li><li> Halten Sie das Leberstück feucht während der Perfusion durch Abdecken mit einem Stück Gaze in Kochsalzlösung eingeweicht. </li><li> Perfundieren mit 1 l Lösung 1 zu spülen, keine remaining Blut in der Leber Stück. </li><li> Ändern Sie den Perfusionsfluid zur Lösung 2 und Perfusion für 10 min. </li><li> Schalten Sie das Perfusionsfluid zu Lösung 3 und Perfusion mit 0,5 L. </li><li> Ändern Sie den Perfusionsfluid zu Lösung 4, die von 0,1 bis 0,15% Kollagenase (Tabelle 2) enthält. </li><li> Für diesen Schritt, Perfusion sollte in einer Umlauf Weise für 9-12 Minuten durchgeführt werden kann oder bis die Leber ausreichend verdaut, das Lebergewebe erscheinen soll unter der Glisson-Kapsel zu leicht auseinander brechen und fühlen sich weich, wenn sie mit der stumpfen Seite einer sondiert Skalpell. </li></ol> 4. Isolierung von Hepatozyten <ol><li> Schalten Sie die Schlauchpumpe und Kanülen entfernen aus der Leber Stück. </li><li> Legen Sie das Stück Leber in eine Kristallisationsschale mit 100-200 ml Lösung 5. </li><li> Entfernen der Glisson-Kapsel vorsichtig und sanft schütteln die Zellen. Wenn es Regionen gibt, die nicht gut durchblutet sind, kann ein Skalpell durchtrennt werdendiese Regionen zu den Zellen enthaltenen freizugeben. Fügen Sie weitere Lösung 5 während des Prozesses, wie gebraucht. </li><li> Noch Lösung 5 bis ein Endvolumen von 500 ml erreicht ist. </li><li> Filter Zellsuspension zweimal, zunächst durch einen 210 um Nylon-Mesh, gefolgt von einer 70 um Nylon-Mesh. Weiter, gießen Sie die Zellsuspension in 200 ml-Zentrifugenröhrchen. </li><li> Zentrifugieren der Zellsuspension bei 72 g für 5 min bei 4 ° C. Überstand wird abgesaugt und vorsichtig resuspendieren Zellpellet vorsichtig in 200 ml Lösung 5. </li><li> Wiederholen Sie den Waschschritt Nummer 4.6 dreimal. Am letzten Zentrifugen Schritt resuspendieren Zellen in Kühllösung (siehe Liste der Materialien). Die Zellen sind etwa 2,5 Millionen Leberzellen pro Milliliter für die Bewertung von Ertrag und Rentabilität mit einer Zählkammer-basierte Trypanblau-Ausschluss-Test sein. </li><li> Zur Durchführung einer Trypanblau-Ausschluss-Assay, fügen Sie 0,1 ml der entsprechend verdünnten Zellen (≈ 2,5 Millionen / ml) zu einem Mikrozentrifugenröhrchen mit 0,5 ml Trypanblau Löauf (0,4% Trypanblau in mit Phosphat gepufferter Salzlösung (PBS) gelöst) und 0,4 ml PBS. Nach dem Mischen der Zellsuspension gründlich, legen Sie eine Zählkammer mit der Suspension und überprüfen unter dem Mikroskop bei 100-facher Vergrößerung. Unter Mikroskopie, werden die toten Zellen blau gefärbt werden, während die lebenden Zellen ungefärbt erscheinen. Zählen Sie die Anzahl der lebenden Zellen und insgesamt in jedem der 1 mm 2 Gitter auf der Hämozytometers markiert. Die Lebensfähigkeit (%), die Ausbeute an lebenden Zellen (Hepatozyten Millionen pro ml kaltem Speicherlösung (CSS) oder Millionen Hepatozyten pro g Leber) können mit den nachfolgenden Formeln berechnet werden. </li></ol><img alt="Gleichung 1" fo:src="/files/ftp_upload/50615/50615eq1highres.jpg" src="/files/ftp_upload/50615/50615eq1.jpg" /> Anmerkung: In diesem Fall ist 10 die Trypanblau-Verdünnungsfaktor und die Zählkammer Faktor beträgt 10.000.

<ol>
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S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-yield+preparation+of+isolated+rat+liver+parenchymal+cells:+a+biochemical+and+fine+structural+study.">High-yield preparation of isolated rat liver parenchymal cells: a biochemical and fine structural study.</a> The Journal of Cell Biology. 43, 506-520 (1969).</li><li>Seglen, P. O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparation+of+Rat-Liver+Cells+.3.+Enzymatic+Requirements+for+Tissue+Dispersion.">Preparation of Rat-Liver Cells .3. Enzymatic Requirements for Tissue Dispersion.</a> Experimental Cell Research. 82 (73), 391-398 (1973).</li><li>Thasler, W. 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=Charitable+State-Controlled+Foundation+Human+Tissue+and+Cell+Research:+Ethic+and+Legal+Aspects+in+the+Supply+of+Surgically+Removed+Human+Tissue+For+Research+in+the+Academic+and+Commercial+Sector+in+Germany.">Charitable State-Controlled Foundation Human Tissue and Cell Research: Ethic and Legal Aspects in the Supply of Surgically Removed Human Tissue For Research in the Academic and Commercial Sector in Germany.</a> Cell and Tissue Banking. 4, 49-56 (2003).</li><li>Queral, A. E., DeAngelo, A. B., Garrett, C. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+different+collagenases+on+the+isolation+of+viable+hepatocytes+from+rat+liver.">Effect of different collagenases on the isolation of viable hepatocytes from rat liver.</a> Analytical Biochemistry. 138, 235-237 (1984).</li><li>Smedsrod, B., Pertoft, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparation+of+Pure+Hepatocytes+and+Reticuloendothelial+Cells+in+High-Yield+from+a+Single-Rat+Liver+by+Means+of+Percoll+Centrifugation+and+Selective+Adherence.">Preparation of Pure Hepatocytes and Reticuloendothelial Cells in High-Yield from a Single-Rat Liver by Means of Percoll Centrifugation and Selective Adherence.</a> J. Leukocyte Biol. 38, 213-230 (1985).</li><li>Cantrell, E., Bresnick, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Benzpyrene+Hydroxylase-Activity+in+Isolated+Parenchymal+and+Nonparenchymal+Cells+of+Rat-Liver.">Benzpyrene Hydroxylase-Activity in Isolated Parenchymal and Nonparenchymal Cells of Rat-Liver.</a> Journal of Cell Biology. 52, 316-321 (1972).</li><li>Weiskirchen, R., Gressner, A. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolation+and+culture+of+hepatic+stellate+cells.">Isolation and culture of hepatic stellate cells.</a> Methods in Molecular Medicine. 117, 99-113 (2005).</li><li>Baccarani, U., 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=Steatotic+versus+cirrhotic+livers+as+a+source+for+human+hepatocyte+isolation.">Steatotic versus cirrhotic livers as a source for human hepatocyte isolation.</a> Transplant P. 33, 664-665 (2001).</li><li>Renz, J. F., 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=Utilization+of+extended+donor+criteria+liver+allografts+maximizes+donor+use+and+patient+access+to+liver+transplantation.">Utilization of extended donor criteria liver allografts maximizes donor use and patient access to liver transplantation.</a> Annals of Surgery. 242, 556-563 (2005).</li><li>Schemmer, P., 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=Extended+donor+criteria+have+no+negative+impact+on+early+outcome+after+liver+transplantation:+a+single-center+multivariate+analysis.">Extended donor criteria have no negative impact on early outcome after liver transplantation: a single-center multivariate analysis.</a> Transplant Proc. 39, 529-534 (2007).</li><li>Alexandre, 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=Influence+of+pre-,+intra-+and+post-operative+parameters+of+donor+liver+on+the+outcome+of+isolated+human+hepatocytes.">Influence of pre-, intra- and post-operative parameters of donor liver on the outcome of isolated human hepatocytes.</a> Cell and Tissue Banking. 3, 223-233 (2002).</li><li>Spotnitz, W. D., Burks, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=State-of-the-art+review:+Hemostats,+sealants,+and+adhesives+II:+Update+as+well+as+how+and+when+to+use+the+components+of+the+surgical+toolbox.">State-of-the-art review: Hemostats, sealants, and adhesives II: Update as well as how and when to use the components of the surgical toolbox.</a> Clinical and applied thrombosis/hemostasis : official journal of the International Academy of Clinical and Applied Thrombosis/Hemostasis. 16, 497-514 (2010).</li><li>Spotnitz, W. D., Burks, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hemostats,+sealants,+and+adhesives+III:+a+new+update+as+well+as+cost+and+regulatory+considerations+for+components+of+the+surgical+toolbox.">Hemostats, sealants, and adhesives III: a new update as well as cost and regulatory considerations for components of the surgical toolbox.</a> Transfusion. 52, 2243-2255 (2012).</li><li>Toriumi, D. M., Raslan, W. F., Friedman, M., Tardy, 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=Histotoxicity+of+cyanoacrylate+tissue+adhesives.+A+comparative+study.">Histotoxicity of cyanoacrylate tissue adhesives. A comparative study.</a> Archives of otolaryngology--head &amp; neck surgery. 116, 546-550 (1990).</li><li>Vinters, H. V., Galil, K. A., Lundie, M. J., Kaufmann, 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=The+histotoxicity+of+cyanoacrylates.+A+selective+review.">The histotoxicity of cyanoacrylates. A selective review.</a> Neuroradiology. 27, 279-291 (1985).</li><li>Bhogal, R. 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=Isolation+of+primary+human+hepatocytes+from+normal+and+diseased+liver+tissue:+a+one+hundred+liver+experience.">Isolation of primary human hepatocytes from normal and diseased liver tissue: a one hundred liver experience.</a> PloS ONE. 6, e18222 (2011).</li><li>Olson, 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=Concordance+of+the+toxicity+of+pharmaceuticals+in+humans+and+in+animals.">Concordance of the toxicity of pharmaceuticals in humans and in animals.</a> Regul. Toxicol. Pharm. 32, 56-67 (2000).</li><li>Koebe, H. G., Pahernik, S. A., Sproede, M., Thasler, W. E., Schildberg, F. 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Optimierung des Protokolls wurde teilweise durch einen Zuschuss aus hepacult GmbH finanziert. Dr. Wolfgang Thasler ist einer der Gründer der hepacult GmbH und bleibt eines der Mitglieder des Vorstandes in dieser Gesellschaft. Die Beschäftigung von Maresa Demmel ist teilweise durch hepacult. Maria Hauner wird durch hepacult GmbH beschäftigt. Hepacult ist ein Spin-off biotechnologische Firma aus der Universität, der humanen Hepatozyten mit Zustimmung und offenen Zugang zu Forschungszwecken bietet.

Dieses Protokoll führt zu der Isolierung von humanen Hepatozyten mit hohen Lebensfähigkeit und Reinheit. Um diese Ergebnisse zu erzielen, ist es wichtig, mit einem geeigneten Stück Leber starten. Das Stück Leber sollte intakt Glisson-Kapsel auf allen Oberflächen außer ein Schnittfläche haben. Ein weiterer wichtiger Faktor ist die bestimmte Charge von Collagenase verwendet werden, wie verschiedene Chargen können deutliche Unterschiede in der Lebensfähigkeit von Hepatozyten nach Aufschluss 11 führen. ...

A correction was made to: <a href="http://www.jove.com/video/50615/isolation-human-hepatocytes-two-step-collagenase-perfusion">Isolation of Human Hepatocytes by a Two-step Collagenase Perfusion Procedure </a>
The changes listed below have been made to Table 1.
1). In the recipe for Solution 2, the Final Concentration of EGTA has been changed from:
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td></td>
			<td>EGTA&#160;</td>
			<td>0.1mM</td>
		</tr>
	</tbody>
</table>
to:
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td></td>
			<td>EGTA&#160;</td>
			<td>1mM</td>
		</tr>
	</tbody>
</table>
2). In the recipes for Solution 3 and 4, the Final Concentration of Calcium chloride dihydrate has been changed from:
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td></td>
			<td>Calcium chloride dihydrate&#160;</td>
			<td>0.5&#181;M</td>
		</tr>
	</tbody>
</table>
to:
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td></td>
			<td>Calcium chloride dihydrate&#160;</td>
			<td>5mM</td>
		</tr>
	</tbody>
</table>

A correction was made to: Isolation of Human Hepatocytes by a Two-step Collagenase Perfusion Procedure.
The Final Concentration of EGTA in Solution 2 and the Final Concentration of Calcium chloride dihydrate in solutions 3 and 4 have been updated in Table 1.

Erratum: Isolation of Human Hepatocytes by a Two-step Collagenase Perfusion Procedure

Eine Leberzellsuspension aus der Leber durch mechanische oder enzymatische Verfahren hergestellt werden. Mechanische Verfahren verwendet werden, um ganze Leberzellen herzustellen, umfassen die Leber zwingt durch Gaze 2, schüttelt ein Leberstück mit Glasperlen in einem Kahn Schüttler 3, mit Glas-Homogenisatoren mit losen Stößel 4,5 usw. Im Laufe der Jahre haben mechanische Methoden aus gefallen begünstigen aufgrund der Schäden an Zellmembranen und der Verlust der Funktion der isolierten Hepatozyten 6,7. Folglich ist die Verwendung eines enzymatischen Verfahrens derzeit die wichtigste Methode zur Isolierung von Hepatozyten. Isolation von Hepatozyten mit einem enzymatischen Verfahren wurde stark verbessert, wenn Berry und Friend 8 durchströmt Kollagenase und Hyaluronidase durch die Leber über die Pfortader in Ratten. Dieses Verfahren verwendet die Perfusion Gefßsystem zu ermöglichen, dass die Enzyme in engen Kontakt mit der Mehrzahl der Zellen kommen, was zueine 6-fache Zunahme der Ausbeute an Hepatozyten 8. Weiterhin ergab diese Methode Zellen, die ihre strukturelle Integrität beibehalten, praktisch ohne Transformation des endoplasmatischen Reticulum in isolierte Bläschen und ohne mitochondriale Schädigungen 8. Diese Methode wurde von Seglen 1, die eine Zwei-Schritt-Verfahren für die Durchblutung der Leber Zellisolierung Pionier modifiziert. In diesem Verfahren wird der Rattenleber mit einem Ca 2 +-freien Puffer, gefolgt von einer Perfusion mit Kollagenase-Puffer, enthaltend Ca 2 + 1 perfundiert. Die Entfernung von Ca 2 + in der ersten Stufe hilft dabei, Desmosomen zu stören, während die Zugabe von Ca 2 + in der zweiten Stufe ist für eine optimale Collagenaseaktivität 1,9 erforderlich. Da die oben beschriebenen veröffentlichte Arbeit wurde bei Ratten durchgeführt wurde, versucht dieser Artikel ein modifiziertes Verfahren, die für die Isolierung von Hepatozyten mit hoher Rentabilität von Summen verwendet werden können, zeigen,Leber ein. Die Verwendung von humanen Hepatozyten bleibt wichtig für die translationale Forschung und für die Validierung von Versuchen mit Tiermodellen. Die menschliche Leber Stücke in dieser Studie verwendet wurden mit Zustimmung der Governance durch das Human Tissue and Cell Research Foundation, einer staatlich kontrollierten Non-Profit-Stiftung 10 erworben. Nach ein Pathologe entfernt, was für die Diagnose erforderlich ist, wurden Leberstücke aus dem verbleibenden Gewebe gesammelt. Die durch den Pathologen geschnittene Gewebe wurde morphologisch nach Leberresektion von Resektionsränder erhalten gesunden Gewebe.

<table border="1">
	<tbody>
		<tr>
			<td>Name of Reagent/Material</td>
			<td>Company</td>
			<td>Catalog Number</td>
			<td>Comments</td>
		</tr>
		<tr>
			<td>Bubble trap</td>
			<td>Ga&szlig;ner Glastechnik</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Glass jacketed condenser</td>
			<td>Ga&szlig;ner Glastechnik</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>41 &deg;C Water bath</td>
			<td>Julabo</td>
			<td>35723-H24/EG</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>37 &deg;C Water bath</td>
			<td>GFL</td>
			<td>1083</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Compressed gas cylinder (95 % O2/5 % CO2)</td>
			<td>Linde</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Gas permeable tubing</td>
			<td>Neolab</td>
			<td>2-4440</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Peristaltic pump</td>
			<td>Ismatec</td>
			<td>IP65</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Scalpel</td>
			<td>Feather</td>
			<td>320010</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Forceps</td>
			<td>Omnilab</td>
			<td>5171014</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Conical flasks 1 L</td>
			<td>Schott Duran</td>
			<td>2121654</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Conical flasks 5 L</td>
			<td>Schott Duran</td>
			<td>2121673</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Beakers</td>
			<td>Schott Duran</td>
			<td>2110654</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>200 ml centrifuge tubes</td>
			<td>Becton Dickinson</td>
			<td>352075</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Crystallizing dish</td>
			<td>Omnilab</td>
			<td>5144063</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Curved irrigation cannulae with ball tips</td>
			<td>Ernst Kratz GmbH</td>
			<td>1464LL/ 1465LL A+B/ 1472LL</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Micro vascular clamps</td>
			<td>Ernst Kratz GmbH</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>B&uuml;chner funnel</td>
			<td>Carl Roth</td>
			<td>HT38.1</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Nylon mesh 210 &mu;m</td>
			<td>Neolab</td>
			<td>4-1413</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Nylon mesh 70 &mu;m</td>
			<td>Neolab</td>
			<td>4-1419</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>0.22 &mu;m sterile filters</td>
			<td>Peske</td>
			<td>99505</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>500 ml bottles</td>
			<td>Schott Duran</td>
			<td>2180144</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>1 L bottles</td>
			<td>Schott Duran</td>
			<td>2180154</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Hemocytometer</td>
			<td>Peske</td>
			<td>06-0001</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>1.5 ml tubes</td>
			<td>Eppendorf</td>
			<td>0030 120,086</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>50 ml conical tubes</td>
			<td>BD Biosciences</td>
			<td>352070</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Ice bucket</td>
			<td>Neolab</td>
			<td>1508454</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Sterile Pasteur pipettes</td>
			<td>Brand</td>
			<td>747715</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Motorised pipette filler (Pipette boy acu)</td>
			<td>Integra</td>
			<td>155017</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Refridgerated centrifuge</td>
			<td>Eppendorf</td>
			<td>5810R</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Laminar flow</td>
			<td>Kendro</td>
			<td>Hera safe-KS9</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Aspirator (Low-flow surgical suction pump)</td>
			<td>Atmos</td>
			<td>C361</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Laboratory Gas Burner</td>
			<td>Integra</td>
			<td>Fire Boy eco</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Disposable laboratory coat</td>
			<td>Paperlynen GmbH</td>
			<td>MD0202414</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Surgical mask with visor</td>
			<td>Kimberly-Clark</td>
			<td>48247</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Surgical hood</td>
			<td>Barrier</td>
			<td>42072</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Latex gloves</td>
			<td>Semper Care</td>
			<td>CE0321</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Collagenase (Batch number NB 4G)</td>
			<td>Serva</td>
			<td>17465</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Calcium chloride dihydrate</td>
			<td>Merck</td>
			<td>2382</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>EGTA</td>
			<td>Sigma</td>
			<td>E4378</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Sodium chloride</td>
			<td>Roth</td>
			<td>9265.2</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Hepes</td>
			<td>Roth</td>
			<td>9105.3</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Potassium chloride</td>
			<td>Serva</td>
			<td>26868</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Albumin</td>
			<td>Biomol</td>
			<td>01400-2</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Glucose</td>
			<td>Serva</td>
			<td>22700</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Sodium hydrogen carbonate</td>
			<td>Serva</td>
			<td>30180</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>0.4% Trypan blue solution</td>
			<td>Lonza</td>
			<td>17-942E</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Cold storage solution</td>
			<td>Hepacult GmbH</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
		</tr>
	</tbody>
</table>

isolation of human hepatocytes by a two-step collagenase perfusion procedure

Die Leber, ein Organ mit einer außergewöhnlichen Regenerationsfähigkeit, führt eine breite Palette von Funktionen, wie zB Entgiftung, Stoffwechsel und Homöostase. Als solche sind Hepatozyten ein wichtiges Modell für eine große Vielfalt von Forschungsfragen. Insbesondere ist die Verwendung von humanen Hepatozyten in den Bereichen Pharmakokinetik, Toxikologie, Leberregeneration und translationale Forschung besonders wichtig. Somit stellt dieses Verfahren eine modifizierte Version einer Zwei-Schritt-Verfahren, um Collagenase-Perfusion isoliert Hepatozyten durch Seglen 1 beschrieben. Früher wurden Hepatozyten durch mechanische Methoden isoliert. Allerdings haben enzymatischen Methoden wurde gezeigt, überlegen zu sein, wie Hepatozyten nach Isolierung behalten ihre strukturelle Integrität und Funktion. Das hier vorgestellte Verfahren passt sich das Verfahren bisher für Rattenlebern der menschlichen Leber Teile und führt zu einer großen Ausbeute von Hepatozyten mit einer Lebensfähigkeit von 77 ± 10% bestimmt. Der HauptUnterschied in diesem Verfahren ist das Verfahren der cannulization der Blutgefäße. Weiterhin kann das hier beschriebene Verfahren auch auf andere Arten von Lebern mit vergleichbaren Leber-und Blutgefäßgrößen angewendet werden.

Perfusion-Setup Die Leberdurchblutung erforderliche Ausrüstung sollte nach 1 gesetzt werden. Die Lebensfähigkeit und Rendite von isolierten menschlichen Hepatozyten Die durchschnittliche Lebensfähigkeit von isolierten humanen Hepatozyten betrug 77 ± 10% und die durchschnittliche Rendite der Hepatozyten war 13 ± 11 Millionen Hepatozyten / g Leber, mit Werten als Mittelwert ± Standardabweichung. Die Zahl der Hepatozyten...

Watch this Scientific Journal Video about Isolation of Human Hepatocytes by a Two-step Collagenase Perfusion Procedure at JoVE.com

Isolation of Human Hepatocytes by a Two-step Collagenase Perfusion Procedure

Eine modifizierte Zwei-Schritt-Kollagenase-Perfusion Verfahren zur Isolierung von humanen Hepatozyten beschrieben. Dieses Verfahren kann auch auf andere Säugetierlebern, angewendet werden. Die isolierten Hepatozyten sind in hoher Ausbeute und Lebensfähigkeit, so dass sie ein geeignetes Modell für die wissenschaftliche Forschung in Bereichen wie der Leberregeneration, Pharmakokinetik und Toxikologie.

Isolierung von humanen Hepatozyten durch eine Zwei-Schritt-Verfahren Collagenase Perfusion

The liver, an organ with an exceptional regeneration capacity, carries out a wide range of functions, such as detoxification, metabolism and homeostasis. ...

isolation-human-hepatocytes-two-step-collagenase-perfusion

Research

JoVE Journal

Biology

30.8K Aufrufe.  Grosshadern Hospital, Munich.  Eine modifizierte Zwei-Schritt-Kollagenase-Perfusion Verfahren zur Isolierung von humanen Hepatozyten beschrieben. Dieses Verfahren kann auch auf andere Säugetierlebern, angewendet werden. Die isolierten Hepatozyten sind in hoher Ausbeute und Lebensfähigkeit, so dass sie ein geeignetes Modell für die wissenschaftliche Forschung in Bereichen wie der Leberregeneration, Pharmakokinetik und Toxikologie. 

Serie: Isolation of Human Hepatocytes by a Two-step Collagenase Perfusion Procedure

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.

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 ...

Forschung

Biologie

Isolation of Rat Portal Fibroblasts by In situ Liver Perfusion

Liver fibrosis is defined by the excessive deposition of extracellular matrix by activated myofibroblasts. There are multiple precursors of hepatic myofibroblasts, including hepatic stellate cells, portal fibroblasts and bone marrow derived fibroblasts 1. Hepatic stellate cells have been the best studied, but portal fibroblasts are increasingly recognized as important contributors to the myofibroblast pool, particularly in biliary fibrosis 2. Portal fibroblasts undergo proliferation in response to biliary epithelial injury, potentially playing a key role in the early stages of biliary scarring 3-5. A method of isolating portal fibroblasts would allow in vitro study of this cell population and lead to greater understanding of the role portal fibroblasts play in biliary fibrosis.
Portal fibroblasts have been isolated using various techniques including outgrowth 6, 7 and liver perfusion with enzymatic digestion followed by size selection 8. The advantage of the digestion and size selection technique compared to the outgrowth technique is that cells can be studied without the necessity of passage in culture. Here, we describe a modified version of the original technique described by Kruglov and Dranoff 8 for isolation of portal fibroblasts from rat liver that results in a relatively pure population of primary cells.

Isolation of Rat Portal Fibroblasts by In situ Liver Perfusion

A technique for isolating portal fibroblasts from rat liver is described. Livers are perfused and digested in situ with collagenase, followed by ex vivo digestion of the liver slurry and size selection of cells. This method provides a pure population of portal fibroblasts without the need for passage in culture.

Isolierung von Ratten-Portal Fibroblasten durch<em&gt; In-situ</em&gt; Leberperfusion

Liver fibrosis is defined  by the excessive deposition of extracellular matrix by activated  myofibroblasts. There are multiple precursors of hepatic ...

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

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

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

Maus Islet der Langerhans Isolation durch eine Kombination von gereinigtem Collagenase und Neutral Protease

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

GST-His purification: A Two-step Affinity Purification Protocol Yielding Full-length Purified Proteins

Key assays in enzymology for the biochemical characterization of proteins in vitro necessitate high concentrations of the purified protein of interest. Protein purification protocols should combine efficiency, simplicity and cost effectiveness1. Here, we describe the GST-His method as a new small-scale affinity purification system for recombinant proteins, based on a N-terminal Glutathione Sepharose Tag (GST)2,3 and a C-terminal 10xHis tag4, which are both fused to the protein of interest. The latter construct is used to generate baculoviruses, for infection of Sf9 infected cells for protein expression5. GST is a rather long tag (29 kDa) which serves to ensure purification efficiency. However, it might influence physiological properties of the protein. Hence, it is subsequently cleaved off the protein using the PreScission enzyme6. In order to ensure maximum purity and to remove the cleaved GST, we added a second affinity purification step based on the comparatively small His-Tag. Importantly, our technique is based on two different tags flanking the two ends of the protein, which is an efficient tool to remove degraded proteins and, therefore, enriches full-length proteins. The method presented here does not require an expensive instrumental setup, such as FPLC. Additionally, we incorporated MgCl2 and ATP washes to remove heat shock protein impurities and nuclease treatment to abolish contaminating nucleic acids. In summary, the combination of two different tags flanking the N- and the C-terminal and the capability to cleave off one of the tags, guaranties the recovery of a highly purified and full-length protein of interest.

In the present protocol, we demonstrate a highly efficient and cost-effective small-scale protein purification method, which allows purification of recombinant proteins by uniquely combining a cleavable GST-tag and a small His-tag.

GST-His-Reinigung: Ein Zwei-Schritt-Affinitätsreinigung Protokoll Nachgeben in voller Länge Gereinigte Proteine

Key assays in enzymology for the biochemical characterization of proteins in vitro necessitate high concentrations of the purified protein of interest. ...

Examination of Drosophila Larval Tracheal Terminal Cells by Light Microscopy

Cell shape is critical for cell function. However, despite the importance of cell morphology, little is known about how individual cells generate specific shapes. Drosophila tracheal terminal cells have become a powerful genetic model to identify and elucidate the roles of genes required for generating cellular morphologies. Terminal cells are a component of a branched tubular network, the tracheal system that functions to supply oxygen to internal tissues. Terminal cells are an excellent model for investigating questions of cell shape as they possess two distinct cellular architectures. First, terminal cells have an elaborate branched morphology, similar to complex neurons; second, terminal cell branches are formed as thin tubes and contain a membrane-bound intracellular lumen. Quantitative analysis of terminal cell branch number, branch organization and individual branch shape, can be used to provide information about the role of specific genetic mechanisms in the making of a branched cell. Analysis of tube formation in these cells can reveal conserved mechanisms of tubulogenesis common to other tubular networks, such as the vertebrate vasculature. Here we describe techniques that can be used to rapidly fix, image, and analyze both branching patterns and tube formation in terminal cells within Drosophila larvae. These techniques can be used to analyze terminal cells in wild-type and mutant animals, or genetic mosaics. Because of the high efficiency of this protocol, it is also well suited for genetic, RNAi-based, or drug screens in the Drosophila tracheal system.

Examination of Drosophila Larval Tracheal Terminal Cells by Light Microscopy

Here, we present a method for light microscopy analysis of tracheal terminal cells in Drosophila larvae. This method allows for quick examination of branch and lumen morphology in whole animals and would be useful for analysis of individual mutants or screens for mutations affecting terminal cell development.

Prüfung der<em&gt; Drosophila</em&gt; Larven Tracheal Terminal-Cells durch Lichtmikroskopie

Cell shape is critical for cell function. However, despite the importance of cell morphology, little is known about how individual cells generate specific ...

Protocol for Isolation of Primary Human Hepatocytes and Corresponding Major Populations of Non-parenchymal Liver Cells

Beside parenchymal hepatocytes, the liver consists of non-parenchymal cells (NPC) namely Kupffer cells (KC), liver endothelial cells (LEC) and hepatic Stellate cells (HSC). Two-dimensional (2D) culture of primary human hepatocyte (PHH) is still considered as the &#34;gold standard&#34; for in vitro testing of drug metabolism and hepatotoxicity. It is well-known that the 2D monoculture of PHH suffers from dedifferentiation and loss of function. Recently it was shown that hepatic NPC play a central role in liver (patho-) physiology and the maintenance of PHH functions. Current research focuses on the reconstruction of in vivo tissue architecture by 3D- and co-culture models to overcome the limitations of 2D monocultures. Previously we published a method to isolate human liver cells and investigated the suitability of these cells for their use in cell cultures in Experimental Biology and Medicine1. Based on the broad interest in this technique the aim of this article was to provide a more detailed protocol for the liver cell isolation process including a video, which will allow an easy reproduction of this technique.
Human liver cells were isolated from human liver tissue samples of surgical interventions by a two-step EGTA/collagenase P perfusion technique. PHH were separated from the NPC by an initial centrifugation at 50 x g. Density gradient centrifugation steps were used for removal of dead cells. Individual liver cell populations were isolated from the enriched NPC fraction using specific cell properties and cell sorting procedures. Beside the PHH isolation we were able to separate KC, LEC and HSC for further cultivation.
Taken together, the presented protocol allows the isolation of PHH and NPC in high quality and quantity from one donor tissue sample. The access to purified liver cell populations could allow the creation of in vivo like human liver models.

A technique to isolate human hepatocytes and non-parenchymal liver cells from the same donor is described. The different liver cell types build the basis for functional liver models and tissue engineering. This new method aims to isolate liver cells in a high yield and viability.

Protokoll für die Isolierung von primären humanen Hepatozyten und entsprechende Hauptpopulationen von Nicht-parenchymale Leberzellen

Beside parenchymal hepatocytes, the liver consists of non-parenchymal cells (NPC) namely Kupffer cells (KC), liver endothelial cells (LEC) and hepatic ...

Microbiota Analysis Using Two-step PCR and Next-generation 16S rRNA Gene Sequencing

The human gut is colonized by trillions of bacteria that support physiologic functions such as food metabolism, energy harvesting, and regulation of the immune system. Perturbation of the healthy gut microbiome has been suggested to play a role in the development of inflammatory diseases, including multiple sclerosis (MS). Environmental and genetic factors can influence the composition of the microbiome; therefore, identification of microbial communities linked with a disease phenotype has become the first step towards defining the microbiome&#8217;s role in health and disease. Use of 16S rRNA metagenomic sequencing for profiling bacterial community has helped in advancing microbiome research. Despite its wide use, there is no uniform protocol for 16S rRNA-based taxonomic profiling analysis. Another limitation is the low resolution of taxonomic assignment due to technical difficulties such as smaller sequencing reads, as well as use of only forward (R1) reads in the final analysis due to low quality of reverse (R2) reads. There is need for a simplified method with high resolution to characterize bacterial diversity in a given biospecimen. Advancements in sequencing technology with the ability to sequence longer reads at high resolution have helped to overcome some of these challenges. Present sequencing technology combined with a publicly available metagenomic analysis pipeline such as R-based Divisive Amplicon Denoising Algorithm-2 (DADA2) has helped advance microbial profiling at high resolution, as DADA2 can assign sequence at the genus and species levels. Described here is a guide for performing bacterial profiling using two-step amplification of the V3-V4 region of the 16S rRNA gene, followed by analysis using freely available analysis tools (i.e., DADA2, Phyloseq, and METAGENassist). It is believed that this simple and complete workflow will serve as an excellent tool for researchers interested in performing microbiome profiling studies.

Described here is a simplified standard operating procedure for microbiome profiling using 16S rRNA metagenomic sequencing and analysis using freely available tools. This protocol will help researchers who are new to the microbiome field as well as those requiring updates on methods to achieve bacterial profiling at a higher resolution.

Mikrobiota-Analyse mit zweistufiger PCR- und 16S-rRNA-Gensequenzierung der nächsten Generation

The human gut is colonized by trillions of bacteria that support physiologic functions such as food metabolism, energy harvesting, and regulation of the ...

A Two-Step Strategy that Combines Epigenetic Modification and Biomechanical Cues to Generate Mammalian Pluripotent Cells

Cell phenotype can be reversed or modified with different methods, with advantages and limitations that are specific for each technique. Here we describe a new strategy that combines the use of chemical epigenetic erasing with mechanosensing-related cues, to generate mammalian pluripotent cells. Two main steps are required. In the first step, adult mature (terminally differentiated) cells are exposed to the epigenetic eraser 5-aza-cytidine to drive them into a pluripotent state. This part of the protocol was developed, based on the increasing understanding of the epigenetic mechanisms controlling cell fate and differentiation, and involves the use of the epigenetic modifier to erase cell differentiated state and then drive into a transient high plasticity window.
In the second step, erased cells are encapsulated in polytetrafluoroethylene (PTFE) micro-bioreactors, also known as Liquid Marbles, to promote 3D cell rearrangement to extend and stably maintain the acquired high plasticity. PTFE is a non-reactive hydrophobic synthetic compound and its use permits the creation of a cellular microenvironment, which cannot be achieved in traditional 2D culture systems. This system encourages and boosts the maintenance of pluripotency though bio-mechanosensing-related cues.
The technical procedures described here are simple strategies to allow for the induction and maintenance of a high plasticity state in adult somatic cells. The protocol allowed the derivation of high plasticity cells in all mammalian species tested. Since it does not involve the use of gene transfection and is free of viral vectors, it may represent a notable technological advance for translational medicine applications. Furthermore, the micro-bioreactor system provides a notable advancement in stem cell organoid technology by in vitro re-creating a specific micro-environment that allows for the long-term culture of high plasticity cells, namely as ESCs, iPSCs, epigenetically erased cells and MSCs.

We here present a method that combines the use of chemical epigenetic erasing with mechanosensing-related cues to efficiently generate mammalian pluripotent cells, without the need of gene transfection or retroviral vectors. This strategy is, therefore, promising for translational medicine and represents a notable advancement in stem cell organoid technology.

Eine zweistufige Strategie, die epigenetische Modifikation und biomechanische Hinweise kombiniert, um pluripotente Zellen von Säugetieren zu erzeugen

Cell phenotype can be reversed or modified with different methods, with advantages and limitations that are specific for each technique. Here we describe ...

Isolation of Primary Rat Hepatocytes with Multiparameter Perfusion Control

Primary hepatocytes are widely used in basic research on liver diseases and for toxicity testing in vitro. The two-step collagenase perfusion procedure for primary hepatocyte isolation is technically challenging, especially in portal vein cannulation. The procedure is also prone to occasional contamination and variations in perfusion conditions due to difficulties in the assembly, optimization, or maintenance of the perfusion setup. Here, a detailed protocol for an improved two-step collagenase perfusion procedure with multiparameter perfusion control is presented. Primary rat hepatocytes were successfully and reliably isolated by taking the necessary technical precautions at critical steps of the procedure, and by reducing the operational difficulty and mitigating the variability of perfusion parameters through the adoption of a special intravenous catheter, standardized sterile disposable tubing, temperature control, and real-time monitoring and alarm system. The isolated primary rat hepatocytes consistently exhibit high cell viability (85%-95%), yield (2-5 x 108 cells per 200-300 g rat) and functionality (albumin, urea and CYP activity). The procedure was complemented by an integrated perfusion system, which is compact enough to be set up in the laminar flow hood to ensure aseptic operation.

This protocol details the use of a special intravenous catheter, standardized sterile disposable tubing, temperature control complemented by real-time monitoring, and an alarm system for two-step collagenase perfusion procedure to improve the consistency in the viability, yield, and functionality of isolated primary rat hepatocytes.

Isolierung primärer Rattenhepatozyten mit Multiparameter-Perfusionskontrolle

Primary hepatocytes are widely used in basic research on liver diseases and for toxicity testing in vitro. The two-step collagenase perfusion procedure ...

Verbesserte Proteinquantifizierung durch zweistufige mitochondriale Isolierung

Two-Step Tag-Free Isolation of Mitochondria for Improved Protein Discovery and Quantification

Most physiological and disease processes, from central metabolism to immune response to neurodegeneration, involve mitochondria. The mitochondrial proteome is composed of more than 1,000 proteins, and the abundance of each can vary dynamically in response to external stimuli or during disease progression. Here, we describe a protocol for isolating high-quality mitochondria from primary cells and tissues. The two-step procedure comprises (1) mechanical homogenization and differential centrifugation to isolate crude mitochondria, and (2) tag-free immune capture of mitochondria to isolate pure organelles and eliminate contaminants. Mitochondrial proteins from each purification stage are analyzed by quantitative mass spectrometry, and enrichment yields are calculated, allowing the discovery of novel mitochondrial proteins by subtractive proteomics. Our protocol provides a sensitive and comprehensive approach to studying mitochondrial content in cell lines, primary cells, and tissues.

Autor im Rampenlicht: Zweistufige tag-freie Isolierung von Mitochondrien für eine verbesserte Proteinentdeckung und -quantifizierung  

We present a two-step protocol for high-quality mitochondria isolation that is compatible with protein discovery and quantification at a proteome scale. Our protocol does not require genetic engineering and is thus suitable for studying mitochondria from any primary cells and tissues.