Questo lavoro è stato reso possibile dal tessuto e Cell Research Foundation umano, che rende i tessuti umani disponibili per la ricerca. Il sostegno finanziario per questo lavoro è stato ricevuto dal Ministero Federale dell&#39;Educazione e della Ricerca (nome di sovvenzione: Virtual Network Fegato, numero di concessione: 0.315.759) e Hepacult GmbH. I nostri ringraziamenti vanno anche agli assistenti tecnici della Banca dei tessuti Grosshadern Hospital per la raccolta dei campioni di fegato e gli assistenti tecnici del isolamento delle cellule Nucleo Fondo per l&#39;esecuzione della perfusione epatica e l&#39;isolamento degli epatociti. In particolare, vorremmo ringraziare Natalja Löwen per dimostrare questa procedura nel video. Infine, vorremmo ringraziare Natalja Löwen e Edeltraud Hanesch per creare le illustrazioni per la figura 1 e le figure nella panoramica schematica del video.

1. Preparazione di perfusione e di isolamento Solutions <ol><li> Preparare le soluzioni richieste per la perfusione del fegato pezzo e l&#39;isolamento di epatociti secondo la Tabella 1. Le soluzioni possono essere conservati a 4 ° C fino all&#39;utilizzo. </li><li> Filtro sterile tutte le soluzioni utilizzando un filtro di 0,22 micron. </li><li> Tutte le soluzioni che vengono a contatto con il fegato devono essere sterili. </li></ol> 2. Preparazione di perfusione apparecchiature e soluzioni <ol><li> L&#39;apparecchiatura per la perfusione del fegato pezzo deve essere montata come mostrato nella Figura 1. </li><li> Il bagno d&#39;acqua dovrebbe essere impostato ad una temperatura appropriata, che è differente in ogni particolare set-up sperimentale, tale che le soluzioni sono alla temperatura di 37 ° C quando raggiungono il pezzo fegato. In questo caso, il bagno di acqua è impostata a 41 ° C per riscaldare le soluzioni 1, 2 e 3 e il condensatore in vetro con camicia. Soluzione 4 deve essere riscaldato fino a37 ° C in un bagno d&#39;acqua separato da utilizzare per ridurre la perdita di attività collagenasi. </li><li> Poco prima di perfusione epatica, accendere il regolatore del serbatoio di gas contenente il 95% O 2/5% di CO 2 a gas l&#39;apparato di ossigenazione (Figura 1E). </li></ol> 3. Perfusione del fegato <ol><li> Un pezzo di fegato con tanto capsula integra di Glisson possibile e idealmente con superficie di 1 solo taglio deve essere ottenuto da un patologo per la perfusione. </li><li> Posizionare questo pezzo fegato sulla imbuto Büchner contenente un filtro a disco forato (Figura 1B). </li><li> Il sistema di perfusione deve essere innescato con Soluzione 1. </li><li> Con una portata bassa, curvo cannule irrigazione con punte oliva deve essere inserito nei vasi sanguigni più grandi sulla superficie di taglio del pezzo fegato. Mentre il sangue vampate dal fegato, il tessuto diventa più chiaro in zone con buona perfusione. Il numero di cannule utilizzati per vari formatidi fegati è mostrato in Figura 2A. La dimensione relativa scelta dovrebbe tradursi in una perfetta aderenza che si terrà il cannule in posizione. I vasi sanguigni più piccoli devono essere lasciati aperti per il buffer di perfusione a fuoriuscire del pezzo fegato. </li><li> Aumentare la portata della pompa peristaltica a tra 110-460 ml / min a seconda delle dimensioni del fegato (Figura 2B). Ciò si traduce in una portata media di 44 ± 16 ml / min per cannula (Figura 2C). La velocità scelta dipende dal pezzo fegato e dovrebbe comportare una lieve plumping up del pezzo fegato. In alcuni casi, può essere necessario bloccare chiuse alcune delle navi aperte con pinze vascolari Micro per ottenere la leggera volumizzante cui sopra. Una buona perfusione può essere osservata quando il pezzo fegato è un colore più chiaro in tutto. </li><li> Tenere il pezzo di fegato umido durante la perfusione coprendolo con un pezzo di garza imbevuta di soluzione fisiologica. </li><li> Profumato con 1 L di soluzione di 1 a stanare ogni remaining sangue nel pezzo fegato. </li><li> Cambiare il liquido di perfusione alla Soluzione 2 e profumato per 10 min. </li><li> Passare il liquido di perfusione alla Soluzione 3 e profumato con 0,5 L. </li><li> Sostituzione del liquido di perfusione alla Soluzione 4, che contiene 0,1-0,15% di collagenasi (Tabella 2). </li><li> Per questo passaggio, perfusione deve essere effettuata in maniera ricircolo per 9-12 minuti o fino a che il fegato è sufficientemente digerito; tessuto epatico dovrebbe apparire a spezzarsi leggermente sotto la capsula di Glisson grafico ammorbidito quando provata con il lato smussato di un bisturi. </li></ol> 4. Isolamento degli epatociti <ol><li> Spegnere la pompa peristaltica e rimuovere cannule dal pezzo di fegato. </li><li> Posizionare il pezzo di fegato in un piatto di cristallizzazione contenente 100-200 ml di soluzione 5. </li><li> Rimuovere la capsula di Glisson con attenzione e scuotere delicatamente le cellule. Se ci sono regioni che non sono ben perfusi, un bisturi può essere usato per tagliarequeste regioni per liberare le cellule contenute all&#39;interno. Aggiungere più Soluzione 5 come necessario durante il processo. </li><li> Aggiungere più Soluzione 5 fino a raggiungere un volume finale di 500 ml. </li><li> Filtro sospensione cellulare due volte prima attraverso una maglia di 210 micron nylon seguita da una rete di nylon 70 micron. Successivamente, versare la sospensione di cellule in 200 ml provette da centrifuga. </li><li> Centrifugare la sospensione cellulare a 72 g per 5 minuti a 4 ° C. Aspirare il surnatante e pellet cellulare delicatamente risospendere delicatamente in 200 ml di soluzione 5. </li><li> Ripetere il numero fase di lavaggio 4.6 tre volte. Nella fase centrifuga finale, risospendere le cellule in soluzione di storage a freddo (vedi elenco dei materiali). Le cellule dovrebbero essere di circa 2,5 milioni di epatociti per millilitro per la valutazione del rendimento e della redditività con un saggio di esclusione trypan blu a base di emocitometro. </li><li> Per eseguire un saggio trypan blue exclusion, aggiungere 0,1 ml di cellule opportunamente diluiti (≈ 2,5 milioni / ml) in una provetta da microcentrifuga contenente 0,5 ml di soluzione molto trypan blu(0.4% blu tripano sciolto in tampone fosfato salino (PBS)) e 0,4 ml di PBS. Dopo aver miscelato accuratamente la sospensione cellulare, caricare un emocitometro con la sospensione ed esaminare al microscopio ad ingrandimento 100X. Sotto microscopio, le cellule morte saranno colorate blu, mentre le cellule vive appaiono senza macchia. Contare il numero di cellule vive e totale indicato in ciascuna 1 mm 2 griglie marcati sul emocitometro. Redditività (%), resa di cellule vive (milioni di epatociti per soluzione di conservazione a freddo ml (CSS) o milioni di epatociti per g di fegato) può essere calcolato utilizzando le formule seguenti. </li></ol><img alt="Equazione 1" fo:src="/files/ftp_upload/50615/50615eq1highres.jpg" src="/files/ftp_upload/50615/50615eq1.jpg" /> Nota: In questo caso, il fattore di diluizione trypan blu è 10 e il fattore emocitometro è 10.000.

<ol>
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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. 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Ottimizzazione di questo protocollo è stato parzialmente finanziato da una sovvenzione Hepacult GmbH. Dr. Wolfgang Thasler è uno dei fondatori di Hepacult GmbH e rimane uno dei membri del consiglio di amministrazione di questa società. L&#39;impiego di Maresa Demmel è parzialmente da Hepacult. Maria Hauner è impiegato da Hepacult GmbH. Hepacult è uno spin-off ditta biotecnologica presso l&#39;Università, che offre epatociti umani con il consenso e aprire l&#39;accesso a fini di ricerca.

Questo protocollo comporta l&#39;isolamento di epatociti umani con alta vitalità e purezza. Per conseguire questi risultati, è importante iniziare con un pezzo adatto di fegato. Il pezzo di fegato dovrebbe avere capsula integra di Glisson su tutte le superfici tranne per 1 superficie di taglio. Un altro fattore importante è la particolare lotto di collagenasi utilizzato, come gruppi differenti possono provocare notevoli differenze Viabilità di epatociti dopo digestione 11. Pertanto, diversi lotti di colla...

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

Una sospensione di cellule di fegato può essere preparato dal fegato con metodi meccanici o enzimatici. Metodi meccanici utilizzati per preparare le cellule del fegato includono intere costringendo il fegato attraverso una garza 2, agitando un pezzo di fegato con perle di vetro in uno shaker Kahn 3, utilizzando omogeneizzatori vetro con pestelli sciolti 4,5 ecc Nel corso degli anni, metodi meccanici sono caduti fuori favorire causa dei danni alle membrane cellulari e la perdita della funzione degli epatociti isolati 6,7. Di conseguenza, l&#39;uso di un metodo enzimatico è attualmente il metodo principale per l&#39;isolamento di epatociti. Isolamento di epatociti utilizzando un metodo enzimatico è stata notevolmente migliorata quando Berry e Friend 8 perfusi collagenasi e ialuronidasi attraverso il fegato attraverso la vena porta nei ratti. Questo processo perfusione utilizzato il sistema vascolare per consentire gli enzimi di entrare in stretto contatto con la maggior parte delle cellule, portando adun aumento di 6 volte della resa degli epatociti 8. Inoltre, questo metodo ha prodotto cellule che mantenevano la loro integrità strutturale, praticamente senza trasformazione del reticolo endoplasmatico in vescicole isolate e nessun danno mitocondriale 8. Questo metodo è stato modificato da Seglen 1, che ha aperto una procedura di perfusione in due fasi per l&#39;isolamento delle cellule epatiche. In questa procedura, il fegato di ratto è perfuso con un Ca 2 + tampone privo seguita da perfusione con collagenasi un tampone contenente Ca 2 + 1. La rimozione di Ca 2 + nel primo passaggio consente di interrompere desmosomi, mentre è necessaria l&#39;aggiunta di Ca 2 + nel secondo passo per un&#39;attività ottimale collagenasi 1,9. Dato che il lavoro pubblicato sopra descritto è stato eseguito su ratti, questo articolo si propone di dimostrare una procedura modificata che può essere utilizzato per l&#39;isolamento di epatociti con alta vitalità da Humun fegati. L&#39;uso di epatociti umani rimane importante per la ricerca traslazionale e per validare gli esperimenti su modelli animali. I pezzi di fegato umano utilizzati in questo studio sono stati acquisiti con il consenso della governance attraverso il tessuto umano e Cell Research Foundation, una controllata dallo Stato fondazione non-profit 10. Dopo un patologo rimosso a quanto necessario per la diagnosi, pezzi di fegato sono stati raccolti dal tessuto rimanente. Il tessuto sezionato fuori dal patologo era morfologicamente il tessuto sano ottenuto da margini di resezione dopo resezione epatica.

<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

Il fegato, un organo con una capacità di rigenerazione eccezionale, svolge un&#39;ampia gamma di funzioni, quali la disintossicazione, il metabolismo e l&#39;omeostasi. Come tale, gli epatociti sono un modello importante per una grande varietà di domande di ricerca. In particolare, l&#39;uso di epatociti umani è particolarmente importante nel campo della farmacocinetica, tossicologia, rigenerazione epatica e ricerca traslazionale. Così, questo metodo presenta una versione modificata di una procedura in due fasi perfusione con collagenasi per isolare epatociti come descritto da Seglen 1. In precedenza, gli epatociti sono stati isolati con metodi meccanici. Tuttavia, i metodi enzimatici hanno dimostrato di essere superiore come epatociti mantengono la loro integrità e la funzione strutturale dopo l&#39;isolamento. Questo metodo qui presentato si adatta il metodo precedentemente progettata per fegati di ratto a pezzi di fegato umano ed i risultati in un grande rendimento di epatociti con agibilità di 77 ± 10%. Il principaledifferenza di questa procedura è il processo di cannulization dei vasi sanguigni. Inoltre, il metodo qui descritto può essere applicato anche ad fegati da altre specie con malattie epatiche o vaso sanguigno dimensioni comparabili.

Setup perfusione Il materiale necessario per la perfusione epatica deve essere impostato secondo la figura 1. La vitalità e rendimento di isolati epatociti umani La redditività media di isolati epatociti umani è stata del 77 ± 10% e il rendimento medio degli epatociti era di 13 ± 11 milioni di epatociti / g di fegato, con i valori espressi come media ± deviazione standard. Il numero di isolamenti epatociti svolto per ...

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

A due fasi procedura di perfusione con collagenasi modificata per l&#39;isolamento di epatociti umani è descritta. Questo metodo può essere applicato anche ad altri fegati mammiferi. Gli epatociti isolati sono disponibili in alta resa e redditività, che li rende un modello adatto per la ricerca scientifica in settori quali la rigenerazione epatica, farmacocinetica e tossicologia.

L&#39;isolamento di epatociti umani da un Two-step Collagenase perfusione procedura

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 Views.  Grosshadern Hospital, Munich.  A due fasi procedura di perfusione con collagenasi modificata per l'isolamento di epatociti umani è descritta. Questo metodo può essere applicato anche ad altri fegati mammiferi. Gli epatociti isolati sono disponibili in alta resa e redditività, che li rende un modello adatto per la ricerca scientifica in settori quali la rigenerazione epatica, farmacocinetica e tossicologia. 

Video: 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.

Derivazione di cellule staminali embrionali umane da 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 ...

Ricerca

Biologia

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.

Isolamento dei fibroblasti Portal ratto<em&gt; In situ</em&gt; Fegato perfusione

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.

Mouse Isolotto di Langerhans isolamento utilizzando una combinazione di Collagenasi depurato e proteasi neutra

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-la sua purificazione: A Two-step Affinity Purification protocollo Cedendo Full-length proteine ​​purificate

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.

Esame della<em&gt; Drosophila</em&gt; Larvali tracheali Terminal cellule al microscopio ottico

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.

Protocollo per l&#39;isolamento di epatociti umani primari e corrispondenti principali popolazioni di cellule del fegato non-parenchimali

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.

Analisi microbiota utilizzando PCR in due fasi e sequenziamento genico rRNA 16S di nuova generazione

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.

Una strategia in due fasi che combina modificazione epigenetica e segnali biomeccanici per generare cellule pluripotenti di mammifero

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.

Isolamento degli epatociti primari di ratto con controllo della perfusione multiparametrica

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

Migliore quantificazione delle proteine grazie all'isolamento mitocondriale in due fasi

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.

Autore in primo piano: Isolamento in due fasi dei mitocondri senza tag per migliorare la scoperta e la quantificazione delle proteine  

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.