Supported by founding from the University of Illinois at Chicago as well as Islet Cell Resource Center NIH grant (RFA-RR 05-003), the Christopher Foundation, the Efroymson Foundation, and the Tellabs Foundation.

1. Purification of islets
<ol>
<li>To start the islet purification procedure, load the COBE bag, clamp all tubes except the green tube, and set the speed to 1,500 and the super out to 0.</li>
<li>In the hood set up the pump and gradient beakers and connect the collection tubing to the green tube.</li>
<li>Now the loading of the ficoll 1.100 can begin: push &ldquo;spin&rdquo; then add 110 ml of Ficoll 1.100 to the front beaker, and start the pump in order to load the COBE bag. As the Ficoll is loaded, press super out, stop the pump, unclamp the pump head and set the super out speed to 100.</li>
<li>When the ficoll reaches the beaker and all air is expelled from the tubing, re-clamp at pump head. Set the spin speed to 3,000, and the super out speed to 0.</li>
<li>Now prepare to load the gradients by pouring the heavy gradient into the front beaker. Slightly release the clamp between the two beakers to remove any air. Then pour the light gradient into the back beaker.</li>
<li>Turn on the magnetic stirrer, press &ldquo;spin&rdquo; on the COBE machine, remove the clamp from the tube connecting the two beakers, and visually verify that the heavy and light gradients are mixing.</li>
<li>Once the gradients started mixing, turn on the centrifuge. Wait one minute, and then turn on the pump to load the mixing gradients.</li>
<li>To load the tissue let the gradient run low in the front beaker, but not low enough to allow air to enter the loading tube, then reclamp the tube connecting the beakers and load the tissue.</li>
<li>Continue adding the rest of the tissue. Then wash the tube that held the tissue with 50 ml of wash solution, and use it to wash the front beaker.</li>
<li>As the last of the tissue enters the bag, simultaneously stop the pump, unclamp at the pump head, and clamp tubing above the bag. Continue to centrifuge for 5 minutes.</li>
<li>While centrifugation continues, bring the 12 collection tubes to the hood and loosen their caps. Attach the collection tubing to the yellow tube, and place the sterile collection tip into conical tube 1. Then unclamp the yellow tube, and clamp the green tube.</li>
<li>When the spin ends, slowly raise Superout to 100. Collect 150 ml in tube 1. Then collect 30 ml in tubes 2-12 (from 200-230 ml).</li>
<li>Once collection is complete, push &ldquo;STOP&rdquo; on the COBE. Now that purification has ended, the islets can be assessed and cultured.</li>
</ol>
2. Sampling and culture
<ol>
<li>After collecting the purified islets fractions, remove a sample from each of the 12 collection tubes and stain with Dithizone. The staining will show which are layers contain high purity islets vs. layers with low purity islets.</li>
<li>Collect the high and low purity tissue and pool each together.</li>
<li>Spin and wash twice. After the second wash, bring the volume of each to 250 ml with Final Wash media.</li>
<li>To assess the pooled fractions start by taking two 1 ml samples from the high of the pooled fractions and one 1 ml sample from the low. Transfer each 1ml sample into a conical tube containing 9 ml of wash solution.</li>
<li>Then transfer 1 ml from each 15 ml tube to a counting dish. Examine and count the cells under the microscope.</li>
<li>After counting the cells calculate the number of flasks needed to culture the islets using the following formula: (total EIN / purity of islets in decimal) / (30,000 EIN per flask). For example, 100,000 islets with 90% purity are cultured in 4 flasks.</li>
<li>Transfer the islets to T175 flasks and culture in a 37&#x02DA;C and 5% CO2 incubator.</li>
</ol>

<ol>
	<li>Shapiro, 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=Islet+transplantation+in+seven+patients+with+type+1+diabetes+mellitus+using+a+glucocorticoid-free+immunosuppressive+regimen.">Islet transplantation in seven patients with type 1 diabetes mellitus using a glucocorticoid-free immunosuppressive regimen.</a> N Engl J Med. 343, 230-238 (2000).</li><li>Nano, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Islet+isolation+for+allotransplantation:+variables+associated+with+successful+islet+yield+and+graft+function.">Islet isolation for allotransplantation: variables associated with successful islet yield and graft function.</a> Diabetologia. 48, 906-912 (2005).</li><li>Barbaro, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Improved+human+pancreatic+islet+purification+with+the+refined+UIC-UB+density+gradient.">Improved human pancreatic islet purification with the refined UIC-UB density gradient.</a> Transplantation. 84, 1200-1203 (2007).</li><li>Lakey, J. R., Rajotte, R. V., Warnock, G. L., Kneteman, N. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Human+pancreas+preservation+prior+to+islet+isolation.+Cold+ischemic+tolerance.">Human pancreas preservation prior to islet isolation. Cold ischemic tolerance.</a> Transplantation. 59, 689-694 (1995).</li><li>Fridell, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+histidine-tryptophan-ketoglutarate+solution+and+University+of+Wisconsin+solution+for+organ+preservation+in+clinical+pancreas+transplantation.">Comparison of histidine-tryptophan-ketoglutarate solution and University of Wisconsin solution for organ preservation in clinical pancreas transplantation.</a> Transplantation. 77, 1304-1306 (2004).</li><li>Potdar, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Initial+experience+using+histidine-tryptophan-ketoglutarate+solution+in+clinical+pancreas+transplantation.">Initial experience using histidine-tryptophan-ketoglutarate solution in clinical pancreas transplantation.</a> Clin Transplant. 18, 661-665 (2004).</li><li>Salehi, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Human+islet+isolation+outcomes+from+pancreata+preserved+with+Histidine-Tryptophan+Ketoglutarate+versus+University+of+Wisconsin+solution.">Human islet isolation outcomes from pancreata preserved with Histidine-Tryptophan Ketoglutarate versus University of Wisconsin solution.</a> Transplantation. 82, 983-985 (2006).</li><li>Ricordi, C., Lacy, P. E., Scharp, D. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Automated+islet+isolation+from+human+pancreas.">Automated islet isolation from human pancreas.</a> Diabetes. 38 Suppl 1, 140-142 (1989).</li><li>Ricordi, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Islet+isolation+assessment+in+man+and+large+animals.">Islet isolation assessment in man and large animals.</a> Acta Diabetol Lat. 27, 185-195 (1990).</li></ol>

In spite of significant advancements in techniques of human islet isolation, islet yield remain highly variable and unpredictable. Purification of digested pancreatic tissue is crucial to recover a sufficient isle mass after successful enzymatic digestion for transplantation. The UIC purification method is recommended because a superior recovery of highly pure human islets was demonstrated by using this method. Moreover, up to 50 ml of digested tissue can be loaded in a single Cobe run for purification, thus minimizing t...

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		<div>
		<table border="1">
		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
		<tbody>
		
<tr>
<td>Centrifuge</td>
<td>equipment</td>
<td>Beckman Coulter</td>
<td>424803</td>
<td>&nbsp;</td>
<tr>
<td>Cobe 2991 Cell Processor</td>
<td>equipment</td>
<td>Gambro. BCT</td>
<td>2556</td>
<td>islet purification</td>
</tr>
<tr>
<td>MZ6 Inverted Microscopy TLBD4.1</td>
<td>equipment</td>
<td>Leica Diagnostic Instrument Co</td>
<td>4103</td>
<td>&nbsp;</td>
<tr>
<td>Cell Culture Dish with 2 mm Grid</td>
<td>equipment</td>
<td>Nunc Brand Products</td>
<td>174926</td>
<td>islet counting</td>
</tr>
<tr>
<td>Digital Sight DS L1</td>
<td>equipment</td>
<td>Nikon</td>
<td>217267</td>
<td>&nbsp;</td>
<tr>
<td>COBE bag</td>
<td>disposable equipment</td>
<td>O.R. Solution</td>
<td>66707003</td>
<td>&nbsp;</td>
<tr>
<td>T175 culture flask</td>
<td>disposable equipment</td>
<td>Sarstedt</td>
<td>83.1812.500</td>
<td>&nbsp;</td>
<tr>
<td>University of Wisconcin (UW) solution</td>
<td>reagent</td>
<td>DURAMED</td>
<td>1000-46-06</td>
<td>&nbsp;</td>
<tr>
<td>Hank's Buffered Salt Solution (HBSS)</td>
<td>reagent</td>
<td>Mediatech Inc</td>
<td>99-597-CM</td>
<td>&nbsp;</td>
<tr>
<td>Ficoll 1.100</td>
<td>reagent</td>
<td>Bichrom AG</td>
<td>L6155</td>
<td>&nbsp;</td>
<tr>
<td>M199 media (wash solution)</td>
<td>reagent</td>
<td>Mediatech Inc</td>
<td>99-784-CM</td>
<td>&nbsp;</td>
<tr>
<td>Final wash/Culture Medium</td>
<td>reagent</td>
<td>Mediatech Inc</td>
<td>99-785-CV</td>
<td>&nbsp;</td>
<tr>
<td>Dithizone</td>
<td>reagent</td>
<td>Sigma </td>
<td>D5130</td>
<td>&nbsp;</td>		</tbody>
		</table>
		</div>

human pancreatic islet isolation: part ii: purification and culture of human islets

Management of Type 1 diabetes is burdensome, both to the individual and society, costing over 100 billion dollars annually. Despite the widespread use of glucose monitoring and new insulin formulations, many individuals still develop devastating secondary complications. Pancreatic islet transplantation can restore near normal glucose control in diabetic patients 1, without the risk of serious hypoglycemic episodes that are associated with intensive insulin therapy. Providing sufficient islet mass is important for successful islet transplantation. However, donor characteristics, organ procurement and preservation affect the isolation outcome 2. At University of Illinois at Chicago (UIC) we developed a successful isolation protocol with an improved purification gradient 3. The program started in January 2004 and more than 300 isolations were performed up to November 2008. The pancreata were sent in cold preservation solutions (UW, University of Wisconsin or HTK, Histidine-Tryptophan Ketoglutarate) 4-7 to the Cell Isolation Laboratory at UIC for islet isolation. Pancreatic islets were isolated using the UIC method, which is a modified version of the method originally described by Ricordi et al 8. As described in Part I: Digestion and Collection of Pancreatic Tissue, human pancreas was trimmed, cannulated, perfused, and digested. After collection and at least 30 minutes of incubation in UW solution, the tissue was loaded in the cell separator (COBE 2991, Cobe, Lakewood, CO) for purification 3. Following purification, islet yield (expressed as islet equivalents, IEQ), tissue volume, and purity was determined according to standard methods 9. Isolated islets were cultured in CMRL-1066 media (Mediatech, Herndon, VA), supplemented with 1.5% human albumin, 0.1% insulin-transferrin-selenium (ITS), 1 ml of Ciprofloxacin, 5 ml o f 1M HEPES, and 14.5 ml of 7.5% Sodium Bicarbonate in T175 flasks at 37&deg;C overnight culture before islets were transplanted or used for research.

Watch this Scientific Journal Video about Human Pancreatic Islet Isolation: Part II: Purification and Culture of Human Islets at JoVE.com

Human Pancreatic Islet Isolation: Part II: Purification and Culture of Human Islets

Achieving high quality and appropriate quantity of human islets is one of the prominent prerequisites for successful islet transplantation. In this video, we describe step by step the procedures for human pancreatic islet isolation (part II: purification and culture of human islets) using a modified automated method.

Management of Type 1 diabetes is burdensome, both to the individual and society, costing over 100 billion dollars annually. Despite the widespread use of ...

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15.4K vistas.  University of Illinois, Chicago. Lograr una alta calidad y la cantidad adecuada de islotes humanos es uno de los requisitos importantes para el trasplante de islotes exitosos. En este video se describe paso a paso los procedimientos para el aislamiento de los islotes pancreáticos humanos (parte II: el saneamiento y la cultura de los islotes), utilizando un método modificado automatizado.

Video: Human Pancreatic Islet Isolation: Part II: Purification and Culture of Human Islets

Murine Pancreatic Islet Isolation

Human Pancreatic Islet Isolation: Part I: Digestion and Collection of Pancreatic Tissue

Management of Type 1 diabetes is burdensome, both to the individual and society, costing over 100 billion dollars annually. Despite the widespread use of glucose monitoring and new insulin formulations, many individuals still develop devastating secondary complications. Pancreatic islet transplantation can restore near normal glucose control in diabetic patients 1, without the risk of serious hypoglycemic episodes that are associated with intensive insulin therapy. Providing sufficient islet mass is important for successful islet transplantation. However, donor characteristic, organ procurement and preservation affect the isolation outcome 2. At University of Illinois at Chicago (UIC) we have developed a successful isolation protocol with an improved purification gradient 3. The program started in January 2004, and more than 300 isolations were performed up to November 2008. The pancreata were sent in cold preservation solutions (UW, University of Wisconsin or HTK, Histidine-Tryptophan Ketoglutarate) 4-7 to the Cell Isolation Laboratory at UIC for islet isolation. Pancreatic islets were isolated using the UIC method, which is a modified version of the method originally described by Ricordi et al 8. Briefly, after cleaning the pancreas from the surrounding tissue, it was perfused with enzyme solution (Serva Collagenase + Neutral Protease or Sigma V enzyme). The distended pancreas was then transferred to the Ricordi digestion chamber, connected to a modified, closed circulation tubing system, and warmed up to 37&deg;C. During the digestion, the chamber was shaken gently. Samples were taken continuously to monitor the digestion progress. Once free islets were detected under the microscope, the digestion was stopped by flushing cold (4&deg;C) RPMI dilution solution (Mediatech, Herndon, VA) into the circulation system to dilute the enzyme. After being collected and washed in M199 media supplemented with human albumin, the tissue was sampled for pre-purification count and incubated with UW solution before purification. Purification process will be described in Part II: Purification and Culture of Human Islets.

Achieving high quality and appropriate quantity of human islets is one of the prominent prerequisites for successful islet transplantation. In this video, we describe step by step the procedures for human pancreatic islet isolation (part I: digestion and collection of pancreatic tissue) using a modified automated method.

Isolation of Stem Cells from Human Pancreatic Cancer Xenografts

Cancer stem cells (CSCs) have been identified in a growing number of malignancies and are functionally defined by their ability to undergo self-renewal and produce differentiated progeny1. These properties allow CSCs to recapitulate the original tumor when injected into immunocompromised mice. CSCs within an epithelial malignancy were first described in breast cancer and found to display specific cell surface antigen expression (CD44+CD24low/-)2. Since then, CSCs have been identified in an increasing number of other human malignancies using CD44 and CD24 as well as a number of other surface antigens. Physiologic properties, including aldehyde dehydrogenase (ALDH) activity, have also been used to isolate CSCs from malignant tissues3-5.
Recently, we and others identified CSCs from pancreatic adenocarcinoma based on
ALDH activity and the expression of the cell surface antigens CD44 and CD24, and CD1336-8. These highly tumorigenic populations may or may not be overlapping and display other functions. We found that ALDH+ and CD44+CD24+ pancreatic CSCs are similarly tumorigenic, but ALDH+ cells are relatively more invasive8. In this protocol we describe a method to isolate viable pancreatic CSCs from low-passage human
xenografts9. Xenografted tumors are harvested from mice and made into a single-cell suspension. Tissue debris and dead cells are separated from live cells and then stained using antibodies against CD44 and CD24 and using the ALDEFLUOR reagent,
a fluorescent substrate of ALDH10. CSCs are then isolated by fluorescence activated cell sorting. Isolated CSCs can then be used for analytical or functional assays requiring viable cells.

Cancer stem cells (CSCs) have been identified in a number of malignancies. In this protocol we describe a flow cytometric method utilizing aldehyde dehydrogenase activity and CD44 and CD24 expression to isolate CSCs from human pancreatic adenocarcinoma xenografts. These viable cells can then be used in functional and analytical studies.

Cancer stem cells (CSCs) have been identified in a growing number of malignancies and are functionally defined by their ability to undergo self-renewal ...

Isolation and Culture of Adult Epithelial Stem Cells from Human Skin

The homeostasis of all self-renewing tissues is dependent on adult stem cells. As undifferentiated stem cells undergo asymmetric divisions, they generate daughter cells that retain the stem cell phenotype and transit-amplifying cells (TA cells) that migrate from the stem cell niche, undergo rapid proliferation and terminally differentiate to repopulate the tissue.
Epithelial stem cells have been identified in the epidermis, hair follicle, and intestine as cells with a high in vitro proliferative potential and as slow-cycling label-retaining cells in vivo 1-3. Adult, tissue-specific stem cells are responsible for the regeneration of the tissues in which they reside during normal physiologic turnover as well as during times of stress 4-5. Moreover, stem cells are generally considered to be multi-potent, possessing the capacity to give rise to multiple cell types within the tissue 6. For example, rodent hair follicle stem cells can generate epidermis, sebaceous glands, and hair follicles 7-9. We have shown that stem cells from the human hair follicle bulge region exhibit multi-potentiality 10.
Stem cells have become a valuable tool in biomedical research, due to their utility as an in vitro system for studying developmental biology, differentiation, tumorigenesis and for their possible therapeutic utility. It is likely that adult epithelial stem cells will be useful in the treatment of diseases such as ectodermal dysplasias, monilethrix, Netherton syndrome, Menkes disease, hereditary epidermolysis bullosa and alopecias 11-13. Additionally, other skin problems such as burn wounds, chronic wounds and ulcers will benefit from stem cell related therapies 14,15. Given the potential for reprogramming of adult cells into a pluripotent state (iPS cells)16,17, the readily accessible and expandable adult stem cells in human skin may provide a valuable source of cells for induction and downstream therapy for a wide range of disease including diabetes and Parkinson's disease.

A rapid, robust way of isolating viable adult epithelial stem cells from human skin is described. The method utilizes enzymatic digestion of skin collagen matrix , followed by plucking of hair follicles and isolation of single cell suspensions or tissue fragments for cell culture.

The homeostasis of all self-renewing tissues is dependent on adult stem cells. As undifferentiated stem cells undergo asymmetric divisions, they generate ...

A Method for Mouse Pancreatic Islet Isolation and Intracellular cAMP Determination

Uncontrolled glycemia is a hallmark of diabetes mellitus and promotes morbidities like neuropathy, nephropathy, and retinopathy. With the increasing prevalence of diabetes, both immune-mediated type 1 and obesity-linked type 2, studies aimed at delineating diabetes pathophysiology and therapeutic mechanisms are of critical importance. The &#946;-cells of the pancreatic islets of Langerhans are responsible for appropriately secreting insulin in response to elevated blood glucose concentrations. In addition to glucose and other nutrients, the &#946;-cells are also stimulated by specific hormones, termed incretins, which are secreted from the gut in response to a meal and act on &#946;-cell receptors that increase the production of intracellular cyclic adenosine monophosphate (cAMP). Decreased &#946;-cell function, mass, and incretin responsiveness are well-understood to contribute to the pathophysiology of type 2 diabetes, and are also being increasingly linked with type 1 diabetes. The present mouse islet isolation and cAMP determination protocol can be a tool to help delineate mechanisms promoting disease progression and therapeutic interventions, particularly those that are mediated by the incretin receptors or related receptors that act through modulation of intracellular cAMP production. While only cAMP measurements will be described, the described islet isolation protocol creates a clean preparation that also allows for many other downstream applications, including glucose stimulated insulin secretion, [3H]-thymidine incorporation, protein abundance, and mRNA expression.

Assaying in vitro &#946;-cell function using isolated mouse islets of Langerhans is an important component in the study of diabetes pathophysiology and therapeutics. While many&#160;downstream applications are available, this protocol specifically describes the measurement of intracellular cyclic adenosine monophosphate (cAMP) as an essential parameter determining &#946;-cell function.

Uncontrolled glycemia is a hallmark of diabetes mellitus and promotes morbidities like neuropathy, nephropathy, and retinopathy. With the increasing ...

Isolation and Culture of Mouse Primary Pancreatic Acinar Cells

This protocol permits rapid isolation (in less than 1 hr) of murine pancreatic acini, making it possible to maintain them in culture for more than one week. More than 20 x 106 acinar cells can be obtained from a single murine pancreas. This protocol offers the possibility to independently process as many as 10 pancreases in parallel. Because it preserves acinar architecture, this model is well suited for studying the physiology of the exocrine pancreas in vitro in contrast to cell lines established from pancreatic tumors, which display many genetic alterations resulting in partial or total loss of their acinar differentiation.

In this publication, we describe a rapid and convenient procedure for isolating and culturing primary pancreatic acinar cells from the murine pancreas. This method constitutes a valuable approach to study the physiology of fresh primary normal/untransformed exocrine pancreatic cells.

This protocol permits rapid isolation (in less than 1 hr) of murine pancreatic acini, making it possible to maintain them in culture for more than one ...

Efficient Production and Purification of Recombinant Murine Kindlin-3 from Insect Cells for Biophysical Studies

Kindlins are essential coactivators, with talin, of the cell surface receptors&#160;integrins and also participate in integrin outside-in signalling, and the control of gene transcription in the cell nucleus. The kindlins are ~75 kDa multidomain proteins and bind to an NPxY motif and upstream T/S cluster of the integrin &#946;-subunit cytoplasmic tail. The hematopoietically-important kindlin isoform, kindlin-3, is critical for platelet aggregation during thrombus formation, leukocyte rolling in response to infection and inflammation and osteoclast podocyte formation in bone resorption. Kindlin-3&#39;s role in these processes has resulted in extensive cellular and physiological studies. However, there is a need for an efficient method of acquiring high quality milligram quantities of the protein for further studies. We have developed a protocol, here described, for the efficient expression and purification of recombinant murine kindlin-3 by use of a baculovirus-driven expression system in Sf9 cells yielding sufficient amounts of high purity full-length protein to allow its biophysical characterization. The same approach could be taken in the study of the other mammalian kindlin isoforms.

Kindlins are fundamental to cell adhesion through integrins but studies of them have been hampered by the difficulty encountered in expressing them recombinantly in bacterial hosts. We describe here methods for their efficient production in baculovirus-infected insect cells.

Kindlins are essential coactivators, with talin, of the cell surface receptors&#160;integrins and also participate in integrin outside-in signalling, and ...

A Simple High Efficiency Protocol for Pancreatic Islet Isolation from Mice

Pancreatic islets, also called the Islets of Langerhans, are a cluster of endocrine cells which produces hormones for glucose regulation and other important biological functions. The islets primarily consist of five types of hormone-secreting cells: &#945; cells secrete glucagon, &#946; cells secrete insulin, &#948; cells secrete somatostatin, &#949; cells secrete ghrelin, and PP cells secrete pancreatic polypeptide. Sixty to 80% of the cells in the islets are &#946; cells, which are the most important cell population to study insulin secretion. Pancreatic islets are a crucial model system to study ex vivo insulin secretion. Acquiring high quality islets is of great importance for diabetes research. Most islet isolation procedures require technically difficult to access site of collagenase injection, harsh and complex digestion procedures, and multiple density gradient purification steps. This paper features a simple high yield mouse islet isolation method with detailed descriptions and realistic demonstrations, showing the following specific steps: 1) injection of collagenase P at the ampulla of Vater, a small area joining the pancreatic duct and the common bile duct, 2) enzymatic digestion and mechanical separation of the exocrine pancreas, and 3) a single gradient purification step. The advantages of this method are the injection of digestive enzyme using the more accessible ampulla of Vater, more complete digestion using combination of enzymatic and mechanical approaches, and a simpler single gradient purification step. This protocol produces approximately 250&#8212;350 islets per mouse; and islets are suitable for various ex vivo studies. Possible caveats of this procedure are potentially damaged islets due to enzymatic digestion and/or prolonged gradient incubation, all of which can be largely avoided by careful ad justification of incubation time.

This islet isolation protocol described a novel route of collagenase injection to digest the exocrine tissue and a simplified gradient procedure to purify the islets from mice. It involves enzymatic digestion, gradient separation/purification, and islet hand-picking. Successful isolation can yield 250&#8211;350 high quality and fully functional islets per mouse.

Pancreatic islets, also called the Islets of Langerhans, are a cluster of endocrine cells which produces hormones for glucose regulation and other ...

Pancreatic Islet Embedding for Paraffin Sections

Experiments using isolated pancreatic islets are important for diabetes research, but islets are expensive and of limited abundance. Islets contain a mixed cell population in a structured architecture that impacts function, and human islets are widely variable in cell type composition. Current frequently used methods to study cultured islets include molecular studies performed on whole islets, lumping disparate islet cell types together, or microscopy or molecular studies on dispersed islet cells, disrupting islet architecture. For in vivo islet studies, paraffin-embedded pancreas sectioning is a powerful technique to assess cell-specific outcomes in the native pancreatic environment. Studying post-culture islets by paraffin sectioning would offer several advantages: detection of multiple outcomes on the same islets (potentially even the exact-same islets, using serial sections), cell-type-specific measurements, and maintaining native islet cell-cell and cell-substratum interactions both during experimental exposure and for analysis. However, existing techniques for embedding isolated islets post-culture are inefficient, time consuming, prone to loss of material, and generally produce sections with inadequate islet numbers to be useful for quantifying outcomes. Clinical pathology laboratory cell block preparation facilities are inaccessible and impractical for basic research laboratories. We have developed an improved, simplified bench-top method that generates sections with robust yield and distribution of islets. Fixed islets are resuspended in warm histological agarose gel and pipetted into a flat disc on a standard glass slide, such that the islets are distributed in a plane. After standard dehydration and embedding, multiple (10+) 4 - 5 &#181;m sections can be cut from the same islet block. Using this method, histological&#160;and immunofluorescent analyses can be performed on mouse, rat, and human islets. This is an effective, inexpensive, time-saving approach to assess cell-type-specific, intact-architecture outcomes from cultured islets.

Ex vivo pancreatic islet studies are important for diabetes research. Existing techniques to study cultured islets in their native 3-dimensional architecture are time consuming, inefficient, and infrequently used. This work describes a new, simple, and efficient method for generating high-quality paraffin sections of whole cultured islets.

Experiments using isolated pancreatic islets are important for diabetes research, but islets are expensive and of limited abundance. Islets contain a ...

Isolation and Enrichment of Human Lung Epithelial Progenitor Cells for Organoid Culture

Epithelial organoid models serve as valuable tools to study the basic biology of an organ system and for disease modeling. When grown as organoids, epithelial progenitor cells can self-renew and generate differentiating progeny that exhibit cellular functions similar to those of their in vivo counterparts. Herein we describe a step-by-step protocol to isolate region-specific progenitors from human lung and generate 3D organoid cultures as an experimental and validation tool. We define proximal and distal regions of the lung with the goal of isolating region-specific progenitor cells. We utilized a combination of enzymatic and mechanical dissociation to isolate total cells from the lung and trachea. Specific progenitor cells were then fractionated from the proximal or distal origin cells using fluorescence associated cell sorting (FACS) based on cell type-specific surface markers, such as NGFR&#160;for sorting basal cells and HTII-280 for sorting alveolar type II cells. Isolated basal or alveolar type II progenitors were used to generate 3D organoid cultures. Both distal and proximal progenitors formed organoids with a colony forming efficiency of 9-13% in distal region and 7-10% in proximal region when plated 5000 cell/well on day 30. Distal organoids maintained HTII-280+ alveolar type II cells in culture whereas proximal organoids differentiated into ciliated and secretory cells by day 30. These 3D organoid cultures can be used as an experimental tool for studying the cell biology of lung epithelium and epithelial mesenchymal interactions, as well as for the development and validation of therapeutic strategies targeting epithelial dysfunction in a disease.

This article provides a detailed methodology for tissue dissociation and cellular fractionation approaches allowing enrichment of viable epithelial cells from proximal and distal regions of the human lung. Herein these approaches are applied for the functional analysis of lung epithelial progenitor cells through the use of 3D organoids culture models.

Epithelial organoid models serve as valuable tools to study the basic biology of an organ system and for disease modeling. When grown as organoids, ...