This study was supported by National Heart, Lung, and Blood Institute Grant HL- 103542, and The BCH Anesthesia Research Foundation&#8217;s Distinguished Trailblazer Award to CAP.

Preparation
<ol>
	<li>Prepare 1 M K-HEPES Stock Solution (adjust pH to 7.2 with KOH).</li>
	<li>Prepare 0.5 M K-EGTA Stock Solution (adjust pH to 8.0 with KOH).</li>
	<li>Prepare 1 M KH2PO4 Stock Solution.</li>
	<li>Prepare 1 M MgCl2 Stock Solution.</li>
	<li>Prepare Homogenizing Buffer (pH 7.2) 300 mM sucrose, 10 mM K-HEPES, and 1 mM K-EGTA. Store at 4 &#176;C.</li>
	<li>Prepare Respiration Buffer 250 mM sucrose, 2 mM KH2PO4, 10 mM MgCl2, 20 mM K-HEPES Buffer (pH 7.2) and 0.5 mM K-EGTA (pH 8.0). Store at 4 &#176;C.</li>
	<li>Prepare 10x PBS Stock Solution by dissolving 80 g of NaCl, 2 g of KCl, 14.4 g of Na2HPO4, and 2.4 g of KH2PO4 into 1 L double distilled H2O (pH 7.4).</li>
	<li>Prepare 1x PBS by pipetting 100 ml 10x PBS into 1 L double distilled H2O.</li>
	<li>Prepare Subtilisin A Stock by weighing out 4 mg of Subtilisin A into a 1.5 ml microfuge tube. Store at -20&#160;&#176;C until use.</li>
	<li>Prepare BSA Stock by weighing out 20 mg of BSA into a 1.5 ml microfuge tube. Store at -20&#160;&#176;C until use.</li>
</ol>
Mitochondrial Isolation (Figure 1)
<ol>
	<li>Immediately prior to isolation, dissolve Subtilisin A in 1 ml of Homogenizing Buffer.</li>
	<li>Immediately prior to isolation, dissolve BSA in 1 ml of Homogenizing Buffer.</li>
	<li>Collect two fresh tissue samples using a 6 mm biopsy sample punch and store in 1x PBS in a 50 ml conical centrifuge tube on ice.</li>
	<li>Transfer the two 6 mm punches of tissue to a dissociation C tube containing 5 ml of ice cold Homogenizing Buffer.</li>
	<li>Homogenize the tissue by fitting the dissociation C tube on the tissue dissociator and select the pre-set mitochondrial isolation cycle (60 sec homogenization).</li>
	<li>Remove the dissociation C tube to an ice bucket.</li>
	<li>Add 250 &#956;l of Subtilisin A Stock Solution to the homogenate, mix by inversion and incubate the homogenate on ice for 10 min.
	<ol>
		<li>Optional in the case that the tissue is fibrous: Centrifuge the solution at 750 x g for 4 min.</li>
	</ol>
	</li>
	<li>Place a 40 &#181;m mesh filter onto a 50 ml conical centrifuge tube on ice and pre-wet the filter with Homogenizing Buffer and filter the homogenate into the 50 ml conical centrifuge tube on ice.</li>
	<li>Add 250 &#181;l of freshly prepared BSA Stock Solution to the filtrate and mix by inversion. 
	Note: Omit this step if mitochondrial protein determination is required.</li>
	<li>Place a 40 &#181;m filter onto a 50 ml conical centrifuge tube on ice and pre-wet the filter with Homogenizing Buffer and filter the homogenate into the 50 ml conical centrifuge tube on ice.</li>
	<li>Place a 10 &#181;m filter onto a 50 ml conical centrifuge tube on ice and pre-wet the filter with Homogenizing Buffer and filter the homogenate into the 50 ml conical centrifuge tube on ice.</li>
	<li>Transfer the filtrate to two pre-chilled 1.5 ml microfuge tubes and centrifuge at 9,000 x g for 10 min at 4 &#186;C.</li>
	<li>Remove supernatant and re-suspend and combine pellets in 1 ml of ice cold Respiration Buffer.</li>
</ol>
ATP Assay
Note: To determine the metabolic activity of isolated mitochondria an ATP luminescence assay can be performed using an ATP assay kit. The protocol, reagents and standards were supplied in the assay kit. A summary of the procedure is described below.
<ol>
	<li>Equilibrate kit reagents to RT.</li>
	<li>Prepare 10 mM ATP Stock Solution by dissolving lyophilized ATP pellet in 1,170 &#181;l of double distilled water. Store ATP standard Stock Solution and prepared mitochondrial samples on ice.</li>
	<li>Add 5 ml of Substrate Buffer solution to a vial of lyophilized substrate solution. Mix gently and place in the dark.</li>
	<li>Add 100 &#181;l of Respiration Buffer to all wells of&#160;a black, opaque bottom, 96 well plate.</li>
	<li>Add 10 &#181;l of mitochondria from the prepared samples to each well of a black, opaque bottom, 96 well plate. Note: Samples are plated in triplicate. Include a row for standards and three wells for the negative control (Respiration Buffer).</li>
	<li>Add 50 &#181;l of mammalian cell lysis solution to all wells, including standards and controls.</li>
	<li>Incubate the plate at 37 &#186;C for 5 min on an orbital shaker at 125 rpm.</li>
	<li>During the incubation prepare ATP standards in concentrations of 0.1 mM, 0.05 mM, 0.01 mM, 0.005 mM, 0.001 mM, and 0.0001 mM ATP from the 10 mM ATP Stock Solution. Store standards on ice.</li>
	<li>Following the incubation, add 10 &#181;l of ATP standards to corresponding wells as indicated on the plate map. Note: Standards are performed in duplicate.</li>
	<li>Add 50 &#181;l of the reconstituted substrate solution to each well.</li>
	<li>Incubate the plate at 37 &#186;C on the orbital shaker for 5 min at 125 rpm.</li>
	<li>Open Gen5 1.11 software on a computer linked with the spectrophotometer.</li>
	<li>Under &#8220;Create a New Item&#8221;, click on &#8220;Experiment&#8221;.</li>
	<li>Click on &#8220;Default Protocol&#8221;. Click &#8220;Ok&#8221;.</li>
	<li>In the left column, select &#8220;Protocol&#8221;, then &#8220;Procedure&#8221;.</li>
	<li>Select &#8220;Delay&#8221;. Set to 00:10:00. Click &#8220;Ok&#8221;.</li>
	<li>Select &#8220;Read&#8221;. Select &#8220;Luminescence&#8221; from drop down menu. Adjust other settings to the following: Read type Endpoint, Integration Time 0:01.00 MM:SS.ss, Filter Sets 1, Emission Hole, Optics Position Top, Sensitivity 100, Top Probe Vertical Offset 1.00 mm.</li>
	<li>When the plate is ready to be analyzed, click the &#8220;Read Plate&#8221; icon on the top row. Click &#8220;Read&#8221;. When the spectrophotometer opens, place the plate into the tray with well A1 in the upper left corner. A box with the temperature will open. Click &#8220;Read&#8221;. Note: Higher values correlate with increased ATP levels and higher metabolic activity.</li>
</ol>

<ol>
	<li>van Loo, G., Saelens, X., van Gurp, M., MacFarlane, M., Martin, S. J., Vandenabeele, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+role+of+mitochondrial+factors+in+apoptosis:+a+Russian+roulette+with+more+than+one+bullet.">The role of mitochondrial factors in apoptosis: a Russian roulette with more than one bullet.</a> Cell Death Differ. 9 (10), 1031-1042 (2002).</li><li>Szabadkai, G., Duchen, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mitochondria:+the+hub+of+cellular+Ca2++signaling.">Mitochondria: the hub of cellular Ca2+ signaling.</a> Physiology (Bethesda). 23, 84-94 (2008).</li><li>Chan, D. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mitochondria:+Dynamic+Organelles+in+Disease,+Aging,+and+Development.">Mitochondria: Dynamic Organelles in Disease, Aging, and Development.</a> Cell. 125 (7), 1241-1252 (2006).</li><li>Picard, M., 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=Mitochondrial+structure+and+function+are+disrupted+by+standard+Isolation+methods.">Mitochondrial structure and function are disrupted by standard Isolation methods.</a> PLoS ONE. 6 (3), e18317 (2011).</li><li>Bensley, R. R., Hoerr, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Studies+on+cell+structure+by+freeze-drying+method;+preparation+and+properties+of+mitochondria.">Studies on cell structure by freeze-drying method; preparation and properties of mitochondria.</a> Anat Rec. 60, 449-455 (1934).</li><li>Claude, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fractionation+of+mammalian+liver+cells+by+differential+centrifugation+II.+Experimental+procedures+and+results.">Fractionation of mammalian liver cells by differential centrifugation II. Experimental procedures and results.</a> J Exp Med. 84 (1), 61-89 (1946).</li><li>Hogeboom, H., Schneider, W. C., Palade, G. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cytochemical+studies+of+mammalian+tissues;+isolation+of+intact+mitochondria+from+rat+liver;+some+biochemical+properties+of+mitochondria+and+submicroscopic+particulate+material.">Cytochemical studies of mammalian tissues; isolation of intact mitochondria from rat liver; some biochemical properties of mitochondria and submicroscopic particulate material.</a> J Biol Chem. 172 (2), 619-635 (1948).</li><li>Ernster, L., Schtaz, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mitochondria:+a+historical+Review.">Mitochondria: a historical Review.</a> J Cell Biol. 91 (3 Pt 2), 227s-255s (1981).</li><li>Pallotti, F., Lenaz, G. <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+subfractionation+of+mitochondria+from+animal+cells+and+tissue+culture+lines.">Isolation and subfractionation of mitochondria from animal cells and tissue culture lines.</a> Methods Cell Biol. 80, 3-44 (2007).</li><li>Schmitt, S., 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=A+semi-automated+method+for+isolating+functionally+intact+mitochondria+from+cultured+cells+and+tissue+biopsies.">A semi-automated method for isolating functionally intact mitochondria from cultured cells and tissue biopsies.</a> Anal Biochem. 443 (1), 66-74 (2013).</li><li>Fern&#225;ndez-Vizarra, E., Ferr&#237;n, G., P&#233;rez-Martos, A., Fern&#225;ndez-Silva, P., Zeviani, M., Enr&#237;quez, 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=Isolation+of+mitochondria+for+biogenetical+studies:+An+update.">Isolation of mitochondria for biogenetical studies: An update.</a> Mitochondrion. 10 (3), 253-262 (2010).</li><li>Graham, J. 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All animals were treated in accordance with current institutional guidelines. We have no competing financial interests to disclose.

To successfully isolate mitochondria using this protocol it is essential to keep all solutions and tissue samples on ice to preserve mitochondrial viability. Even when maintained on ice, isolated mitochondria will exhibit a decrease in functional activity over time19. We recommend that all solutions and additions be pre-prepared. We pre-weigh and store Subtilisin A in 4 mg aliquots in 1.5 ml microfuge tubes and store them at -20 &#176;C. Similarly BSA is pre-weighed and stored in 20 mg aliquots in 1.5 ml microfuge tubes that can be stored at -20 &#176;C. Just prior to use the tubes are removed from -20&#160;&#176;C and Subtilisin A and BSA are dissolved in 1 ml of Homogenizing Buffer for use in the mitochondrial isolation procedure.
Two biopsy punches from skeletal muscle tissue obtained using a 6 mm biopsy punch provide sufficient mitochondria for use in clinical and surgical procedures for therapeutic interventions17-18. To estimate the number of mitochondria we have used two methods, hemocytometer and particle size counting. The use of particle size counting is recommended. The particle size counter uses electrical impedance to measure the volume of particles passing through an aperture of a defined size. The particle size counter is costly but provides accurate and reliable estimates and is user independent. Mitochondrial number estimated by hemocytometry is more economical. Our studies have demonstrated that this method provides variable estimates that are approximately one order of magnitude less than that obtained using a particle size counter. We have also noted that counts obtained by hemocytometer are highly dependent on the user. We suggest that to ensure consistent estimates all counts using a hemocytometer should be performed by one person.
We have found ATP assay kits to be useful for determining mitochondrial function. The kit supplies all necessary reagents and provides a simple and fast method for determining the metabolic activity of isolated mitochondria. The ATP assay provides similar results as those obtained using a Clark-type electrode and therefore is compatible with previous data analysis20-21.
A major advantage of our mitochondrial isolation protocol is that it allows for isolation of a high yield of viable, respiration competent mitochondria free of contamination in less than 30 min. Differential filtration in place of differential centrifugation significantly reduces procedure time. Other protocols incorporate several centrifugation steps with overall isolation time being 60 min to 100 min13-17. Another advantage of this protocol is that tissue homogenization is standardized. The commercial tissue dissociator provides a standardized cycle and yields consistent and reproducible results. This is in contrast to manual homogenization that is subject to user variability and inconsistency. Our method for the rapid isolation of mitochondria using tissue dissociation and differential filtration provides an isolation time frame compatible for clinical and surgical therapeutic intervention17,18.

A correction was made to: <a href="https://www-jove-com.remotexs.ntu.edu.sg/video/51682">Rapid Isolation And Purification Of Mitochondria For Transplantation By Tissue Dissociation And Differential Filtration.</a> An optional step was added to step 7 of the &#39;Mitochondrial Isolation&#39; section of the protocol. The step is:
1. Optional in the case that the tissue is fibrous: Centrifuge the solution at 750 x g for 4 min.

A correction was made to: Rapid Isolation And Purification Of Mitochondria For Transplantation By Tissue Dissociation And Differential Filtration.

Erratum: Rapid Isolation And Purification Of Mitochondria For Transplantation By Tissue Dissociation And Differential Filtration

Mitochondria exist in every cell in the body except red blood cells and are involved in a large number of important cellular and metabolic processes1-4. Because of these many functions, mitochondrial damage can have detrimental effects3. In order to investigate mitochondrial function and dysfunction several mitochondrial isolation methods have been described. The earliest published accounts of mitochondrial isolation date to the 1940s5-8. The first documented attempt demonstrated mitochondrial isolation by grinding liver tissue in a mortar followed by centrifugation in a salt solution at low speed5,8. Later, other groups expanded upon the original procedure and demonstrated tissue fractionation based on differential centrifugation6-8. These early methods formed the basis of current techniques which often incorporate homogenization, and/or differential centrifugation9-15. The number of homogenization and centrifugation steps varies among protocols. These repetitive steps increase the time for mitochondrial isolation and ultimately reduce viability. In addition, manual homogenization can cause mitochondrial damage and inconsistent results if not properly controlled10,16.
Recently, we used homogenization and differential centrifugation to isolate mitochondria for transplantation into myocardial tissue17,18. This lengthy isolation procedure required approximately 90 min and the clinical applicability of this method was therefore limited. To allow for acute therapeutic use in clinical and surgical treatment we have developed a rapid mitochondrial isolation procedure that can be performed in less than 30 min.
The major benefits of this protocol are that standardized tissue dissociation allows for uniform and consistent homogenization of tissue that is not easily achieved with manual homogenization. In addition, the use of differential filtration in place of differential centrifugation eliminates time consuming and repetitive centrifugation steps allowing for more rapid isolation of highly purified, viable and respiration competent mitochondria.
The ability to isolate viable and respiration competent mitochondria in less than 30 min allows for clinical applicability. This isolation protocol has potential for use in coronary artery bypass grafting surgery (CABG) and other therapeutic procedures.

<table border="0" cellpadding="0" cellspacing="0" width="933">
	<tbody>
		<tr height="20">
			<td height="20" style="height:20px;width:377px;">Sucrose</td>
			<td style="width:181px;">Sigma Aldrich</td>
			<td style="width:147px;">84100</td>
			<td style="width:229px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">HEPES</td>
			<td>Sigma Aldrich</td>
			<td>H4034</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">EGTA</td>
			<td>Sigma Aldrich</td>
			<td>E4378</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Substilsin A</td>
			<td>Sigma Aldrich</td>
			<td>P5380</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">BSA</td>
			<td>Sigma Aldrich</td>
			<td>A7906</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">KH2PO4</td>
			<td>Sigma Aldrich</td>
			<td>P5379</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">MgCl2</td>
			<td>Sigma Aldrich</td>
			<td>M8266</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">NaCl</td>
			<td>Sigma Aldrich</td>
			<td>S6191</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">KCl</td>
			<td>Fisher Scientific</td>
			<td>P2173</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Na2HPO4</td>
			<td>Fisher Scientific</td>
			<td>S374</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:377px;">ATPlite Luminescence Assay System, 
			1000 Assay Kit</td>
			<td>Perkin Elmer</td>
			<td>6016941</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Equipment</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">50 mL Conical Tubes</td>
			<td>BD</td>
			<td>352098</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">40 &#956;m Nylon Filters</td>
			<td>BD&#160;</td>
			<td>352340</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">GentleMACS C tube</td>
			<td>Miltenyl Biotech</td>
			<td>120-005-331</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">1.5 mL Eppendorf tube</td>
			<td>Fisher Scientific</td>
			<td>05-408-129</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">6 mm biopsy punch</td>
			<td>Miltex</td>
			<td>33-36</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">10 &#956;m Pluristrainer</td>
			<td>Pluriselect</td>
			<td>43-500-10-03</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Eppendorf Centrifuge 5415C</td>
			<td>Marshall Scientific</td>
			<td>EP-5415C&#160;</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">GentleMACS Dissociator&#160;</td>
			<td>Miltenyl Biotech</td>
			<td>130-093-235</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">96-well plates, tissue culture treated</td>
			<td>VWR</td>
			<td>82050-732</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Rotomax 120 orbital shaker</td>
			<td>Heidolph</td>
			<td>544-41200-00</td>
			<td></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;">Synergy H4 Hybrid Multi-Mode 
			&#160;Microplate Reader</td>
			<td>BioTek</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Multisizer 4 Coulter Counter</td>
			<td>Beckman Coulter</td>
			<td>A63076</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Oxytherm System</td>
			<td>Hansatech Instruments</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Hemacytometer</td>
			<td>Fisher Scientific</td>
			<td>267110</td>
			<td></td>
		</tr>
	</tbody>
</table>

rapid isolation and purification of mitochondria for transplantation by tissue dissociation and differential filtration

Previously described mitochondrial isolation methods using differential centrifugation and/or Ficoll gradient centrifugation require 60 to 100 min to complete. We describe a method for the rapid isolation of mitochondria from mammalian biopsies using a commercial tissue dissociator and differential filtration. In this protocol, manual homogenization is replaced with the tissue dissociator&#8217;s standardized homogenization cycle. This allows for uniform and consistent homogenization of tissue that is not easily achieved with manual homogenization. Following tissue dissociation, the homogenate is filtered through nylon mesh filters, which eliminate repetitive centrifugation steps. As a result, mitochondrial isolation can be performed in less than 30 min. This isolation protocol yields approximately 2 x 1010 viable and respiration competent mitochondria from 0.18 &#177; 0.04 g (wet weight) tissue sample.

A figure outlining the procedural steps in the isolation of mitochondria using tissue dissociation and differential filtration is shown in Figure 1. Total procedural time is less than 30 min.
Tissue samples were obtained using a 6 mm biopsy punch. Tissue weight was 0.18 &#177; 0.04 g (wet weight). The number of mitochondria isolated as determined by particle size counting was 2.4 x 1010 &#177; 0.1 x 1010 mitochondria for skeletal muscle and 2.75 x 1010 &#177; 0.1 x 1010 mitochondria for liver preparations (Figure 2A). To allow for comparison mitochondrial number was also determined by hemocytometer. Mitochondrial number was underestimated as determined by hemocytometer as 0.11 x 1010 &#177; 0.04 x 1010 mitochondria for skeletal muscle and 0.34 x 1010 &#177; 0.09 x 1010 mitochondria for liver preparations (Figure 2A). Mitochondrial diameter as determined by size based particle counter is shown in Figure 2B. The representative tracing shows the isolated mitochondria are localized under one peak with mean diameter of 0.38 &#177; 0.17 &#181;m in agreement with previous reports7.
Mitochondrial protein/g (wet weight) starting tissue as determined by Bicinchoninic Acid (BCA) assay was 4.8 &#177; 2.9 mg/g (wet weight) and 7.3 &#177; 3.5 mg/g (wet weight) for skeletal muscle and liver samples respectively (Figure 2C).
Mitochondrial purity was determined by transmission electron microscopy and is shown in Figure 2D. Mitochondria are shown to be electron dense with less than 0.01% being fractured or damaged. Contamination by non-mitochondrial particles is less than 0.001%.
Mitochondrial viability was determined by MitoTracker Red as previously described17,18. Our results show that the isolated mitochondria maintain membrane potential (Figures 3A - C).
ATP was determined using a luminescent assay kit. A plate map for the ATP assay is shown in Figure 4. ATP standards were plated in duplicate. Mitochondrial samples and negative controls were plated in triplicate. ATP content was 10.67&#177; 4.38 nmol/mg mitochondrial protein and 14.83 &#177; 4.36 nmol/mg mitochondrial protein for skeletal muscle and liver samples respectively (Figure 3D).
Mitochondrial respiration was assessed using a Clark type electrode as previously described17,18. Mitochondrial oxygen consumption rate was 178 &#177; 17 nM O2/min/mg mitochondrial protein for skeletal muscle and 176 &#177; 23 nM O2/min/mg mitochondrial protein for liver preparations. Respiratory control index (RCI) values were 2.45 &#177; 0.34 and 2.67 &#177; 0.17 for skeletal muscle and liver sample preparations respectively (Figure 3E). These results are similar to those reported in our previous studies using manual homogenization and differential centrifugation to isolate mitochondria17-18.
<img alt="Figure 1" fo:content-width="5in" src="/files/ftp_upload/51682/51682fig1highres.jpg" width="600" /> 
Figure 1.&#160;Schema for the isolation of mitochondria using tissue dissociation and differential filtration. (A)&#160;Transfer two 6 mm biopsy sample punches to 5 ml of Homogenizing Buffer in a dissociation C tube and homogenize the samples using the tissue dissociator&#39;s 1 min homogenization program. (B)&#160;Add 250&#160;&#181;l Subtilisin A stock solution to the homogenate in the dissociation C tube and incubate on ice for 10 min. (C)&#160;Filter the homogenate through a pre-wetted 40 &#181;m mesh filter in a 50 ml conical centrifuge tube on ice and then add 250 &#181;l of BSA stock solution to the filtrate. (D)&#160;Re-filter the filtrate through a new pre-wetted 40 &#181;m mesh filter in a 50 ml conical centrifuge on ice. (E)&#160;Re-filter the filtrate through a new pre-wetted 10 &#181;m mesh filter in a 50 ml conical centrifuge tube on ice. (F)&#160;Transfer the filtrate to 1.5 ml microfuge tubes and centrifuge at 9,000 x g for 10 min at 4&#160;&#176;C. (G)&#160;Remove the supernatant and re-suspend and combine the mitochondrial pellets in 1 ml Respiration Buffer. Total procedure time is less than 30 min. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/51682/51682fig1highres.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 2" fo:content-width="5in" src="/files/ftp_upload/51682/51682fig2highres.jpg" width="600" /> 
Figure 2.&#160;Mitochondrial yield and purity. (A)&#160;Hemocytometer and particle size counter mitochondria number isolated from 0.18 &#177; 0.04 g tissue (wet weight) for skeletal muscle and liver. (B)&#160;Mitochondrial size (mg/g) distribution as detected by particle size counter. (C) Mitochondrial protein mg/g tissue wet weight for skeletal muscle and liver. (D) Transmission electron microscopy image of isolated mitochondria. Scale bar is 100 nm. Arrows indicate possible contamination by non mitochondrial particles and damaged mitochondria. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/51682/51682fig2highres.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 3" fo:content-width="5in" src="/files/ftp_upload/51682/51682fig3highres.jpg" width="600" /> 
Figure 3.&#160;Mitochondrial viability. Representative photomicrographs of isolated mitochondria (A) under phase contrast illumination and (B and C) under fluorescence, with mitochondria labeled with MitoTracker Red CMXRos. Scale bars are 25 &#956;m (A, B) and 5 &#956;m (C). These images indicate that mitochondria maintained membrane potential.&#160;Arrows indicate mitochondria lacking membrane potential or debris&#160;(D) ATP content nmol/mg mitochondrial protein as determined by ATP assay and (E) RCI (state 3/state 4) as determined by Clark electrode. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/51682/51682fig3highres.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 4" fo:content-width="6in" src="/files/ftp_upload/51682/51682fig4highres.jpg" width="600" /> 
Figure 4.&#160;Plate map for ATP assay. This plate map illustrates how to set up standards (A1 - A12), mitochondria samples (B1 - C6), and negative controls (C7 - C9) for the ATP assay. During the assay, 100 &#181;l of Respiration Buffer, 50 &#181;l of mammalian cell lysis solution and 50 &#181;l of reconstituted substrate solution are added to all wells (A1 - C9).

Watch this Scientific Journal Video about Rapid Isolation And Purification Of Mitochondria For Transplantation By Tissue Dissociation And Differential Filtration at JoVE.com

Rapid Isolation And Purification Of Mitochondria For Transplantation By Tissue Dissociation And Differential Filtration

A method for rapid isolation of mitochondria from mammalian tissue biopsies is described. Rat liver or skeletal muscle preparations were homogenized with a commercial tissue dissociator and mitochondria were isolated by differential filtration through nylon mesh filters. Mitochondrial isolation time is &#60;30 min compared to 60 - 100 min using alternative methods.

Previously described mitochondrial isolation methods using differential centrifugation and/or Ficoll gradient centrifugation require 60 to 100 min to ...

rapid-isolation-purification-mitochondria-for-transplantation-tissue

Nanyang Technological University

Research

JoVE Journal

Biology

37.9K Views.  Beth Israel Deaconess Medical Center and Harvard Medical School. A method for rapid isolation of mitochondria from mammalian tissue biopsies is described. Rat liver or skeletal muscle preparations were homogenized with a commercial tissue dissociator and mitochondria were isolated by differential filtration through nylon mesh filters. Mitochondrial isolation time is 

Video: Rapid Isolation And Purification Of Mitochondria For Transplantation By Tissue Dissociation And Differential Filtration

Isolation and Transplantation of Hematopoietic Stem Cells (HSCs)

Isolation and Transplantation of Hematopoietic Stem Cells HSCs

I am Christina Ceso. I am a postdoc in David's Den lab and I work on the hematopoietic stem cells. Today we are going to purify long-term recuperating hematopoietic stem cells and we'll transplant them into a mouse.We start by spraying the mice with alcohol so that first of all, the mind starts sterilized and also the hair doesn't interfere with the dissection. We use PBS with 2%serum for the dissection. I cut the back skin and I pull the skin apart in order to expose the tissue.In order to isolate the tibia, I hold the tibia with tweezers. I cut the tendon on top of the knee and I cut the muscles below the knee and after that I cut through the knee so that the TBI is not connected to the rest of the limb anymore and I pull in order to isolate it. I then hold the TB upside down and with the scissors I separate the foot from the tibia In order to obtain the femur.I cut the muscles around the femur and then I dislocate the femur from the hip. In order to isolate the hip, I cut the muscle around the hip bone on the side of the tail of the mouse and then I pull the hip away from the body of the mouth In order to isolate the spine. I cut through the tail as close as I can to the beginning of the back and then I cut on the two sides of the spine and below the spine, trying to stay as close as possible to the spine so that the peritoneum is not cut and the intestine is left untouched.A first round of cleaning of the bones is done with a scalpel, which is used to scrape the bone, the muscles away from the bone. The scalpel is good to clean the femurs, the hip and the spine. In order to clean the tibia, I hold them with forceps and I use the forceps to remove as much tissue as possible.A second round of cleaning is done using clean wipe to completely clean the bones outta the muscle, and I use the F wipe to clean the tibia, the femurs and the hips. So this is how bones look. After cleaning, I prefer 50 amount tubes with filters on top and I transfer the bones into the mortar.I add the section media and I crush the bones ask of the first round of crashing of the bones. I piped the mixture in order to release as many styles as possible into solution and reduce clumps. I transferred the mixture on the tubes through the filters and this is what the bone fragments look like after the first round of crushing.So I add more dissection medium to the bone fragments and I flash them again. I transferred the seline mixture to the tubes through the filters and at this point the remaining bone fragments are white and there is no bone marrow left. The tubes are filled with PBS 2%serum and in order to have them all with the same weight so that they're balanced in the centrifuge, but also in order to wash the filters so that we obtain as many cells as possible, I then centrifuge the cell mixture and after centrifugation, the palt includes the bone marrow cells.I aspirate the medium and I move back and forward the tube on the rack so that the pelle is becomes loose and fewer clamps are formed. When I add medium, at this point I add one ml of medium per tube and I ics since I'm sorting hematopoietic stem cells. Later on, I'm going to store an ALI output of total bone marrow sizes at this point, which I will use later for the fact single color control.I add lineage antibody cocktail. I ordered the samples to mix them well and I invaded four degrees for 15 minutes. In the meantime, I start preparing the columns for the lineage division.I put the columns on the magnet and I prepare Ian tubes under the columns. I also prepared the gas PBS using aster flip filter and attaching it to the vacuum so that all the bubbles of air move in the top part of the filter. I then add three ml of the gas DBS to each column in order for the column to become wet.After the incubation with the antibodies, I add medium to the cell samples and I centrifuge them in order to remove the excess of antibodies. After the centrifugation, the stain cells are in the pallet. I aspirate the medium and I suspend the pallet in one mile of the gas PBSI Add the strip tab beans, I mix the cells and I incubate for 15 minutes at four degrees.After the incubation, I put new elucian tubes under the columns. I add two ml of PBS to each tube with the cells and I transferred the cell mixture to the column through a 40 micron filter. I wash the tubes with more medium in order to collect all the cells remaining and I apply the remaining medium through the filters to the columns.The progenitor cells lineage low are alluded into the collection views. I pulled the luted samples and I sent tofu them. So after the centrifugation, the depleted cells are in a white pate.I aspirate the medium and re suspend the cells. I store an adequate of the depleted cells and I add the antibodies to the cell mixture for the sorting and also to all the single color controls. The antibodies are incubated in that with the size for 15 minutes in the fridge.After the ation, I add medium to the cells and and centrifuge them to remove the ex excess of antibodies. After the centrifugation, the cells are in the pt, I aspirate the media that I suspend the cells and I transfer the cells into fox tubes with a blue filter. At this point, the cells are ready to be sorted.I place, I place the mouse under a heating lamp for a few minutes so that the veins dilate and they are more easily seen. When preparing the syringe, you have to be careful to eliminate all the bubbles from the, the mixture that is in the syringe and then you bend the needle at 90 degrees. I put the mouse under a glass cup with a weight on top so that it can run away.I sterilize the tail with the alcohol pad so that the site of injection is sterile, but also it's easier to identify the vein. If you look at the tail of the mouse from the top in the middle and top of the tail, there is an artery while on the two sides there are the two veins and we inject the cells in one of the two veins. I insert the needle into the vein and I inject following injection.It is to wait for a couple of seconds before removing the needle, the needle, and after that I clean the side of injection. This is a representation of the syringe with the ben needle bent at 90 degrees with the knee, the at this ankle compared to the tail, which makes the injection the easiest. When you injecting the tail of the mouse, you have to keep in mind that the tail vein is extremely superficial, so really this is the orientation of the needle compared to the tail.And it looks like you will just keep sliding on top of the tail, but actually you will get into the tail then. I am Christina Ceso. I am a post in David Kaden lab, and I work on the hematopoietic stem cells.I usually use for animals to start with, and I had more variability at the beginning, but once you become consistent with your methods, I consistently get about 50, 000 to 60, 000 stem cells out for mice. I did my PhD in London with Dr.Fiona Wat working on derma stem cells. After that, I just wanted to have a wider knowledge of adult stem cells in various tissues, and so I decided to move to David Kaden lab to work on hematopoietic stem cells, mainly because the things that are known about hematopoietic stem cells are the things that are not known for the epidermic stem cells and a number of assays that can be done with epi.Epidermal stem cells are not really done yet with the hematopoietic stem cells, and so at this point I'm trying to put together the, the knowledge from the two different fields and ultimately I'm interested in the study of the mechanism to regulate adult tissue sensors in general, so not just the epidermis or the stem cells, but also different tissues because there are, there are similar mechanism that is, it's always the same genes that are involved in the regulation that just interact with each other in different ways, and it's just interesting to understand what makes each stem cell be a stem, but then ultimately a stem cell in a different tissue. So giving rise to a different protein.

Staining of Proteins in Gels with Coomassie G-250 without Organic Solvent and Acetic Acid

In classical protein staining protocols using Coomassie Brilliant Blue (CBB), solutions with high contents of toxic and flammable organic solvents (Methanol, Ethanol or 2-Propanol) and acetic acid are used for fixation, staining and destaining of proteins in a gel after SDS-PAGE. To speed up the procedure, heating the staining solution in the microwave oven for a short time is frequently used. This usually results in evaporation of toxic or hazardous Methanol, Ethanol or 2-Propanol and a strong smell of acetic acid in the lab which should be avoided due to safety considerations. In a protocol originally published in two patent applications by E.M. Wondrak (US2001046709 (A1), US6319720 (B1)), an alternative composition of the staining solution is described in which no organic solvent or acid is used. The CBB is dissolved in bidistilled water (60-80mg of CBB G-250 per liter) and 35 mM HCl is added as the only other compound in the staining solution. The CBB staning of the gel is done after SDS-PAGE and thorough washing of the gel in bidistilled water. By heating the gel during the washing and staining steps, the process can be finished faster and no toxic or hazardous compunds are evaporating. The staining of proteins occurs already within 1 minute after heating the gel in staining solution and is fully developed after 15-30 min with a slightly blue background that is destained completely by prolonged washing of the stained gel in bidistilled water, without affecting the stained protein bands.

A short protocol for protein staining with Coomassie Brilliant Blue (CBB) G-250 in polyacrylamide gels is described without using organic solvents or acetic acid as in the classical staining procedures with CBB.

In classical protein staining protocols using Coomassie Brilliant Blue (CBB), solutions with high contents of toxic and flammable organic solvents ...

Purification of Mitochondria from Yeast Cells

Mitochondria are the main site of ATP production during aerobic metabolism in eukaryotic non-photosynthetic cells1. These complex organelles also play essential roles in apoptotic cell death2, cell survival3, mammalian development4, neuronal development and function4, intracellular signalling5, and longevity regulation6. Our understanding of these complex biological processes controlled by mitochondria relies on robust methods for assessing their morphology, their protein and lipid composition, the integrity of their DNA, and their numerous vital functions. The budding yeast Saccharomyces cerevisiae, a genetically and biochemically manipulable unicellular eukaryote with annotated genome and well-defined proteome, is a valuable model for studying the molecular and cellular mechanisms underlying essential biological functions of mitochondria. For these types of studies, it is crucial to have highly pure mitochondria. Here we present a detailed description of a rapid and effective method for purification of yeast mitochondria. This method enables the isolation of highly pure mitochondria that are essentially free of contamination by other organelles and retain their structural and functional integrity after their purification. Mitochondria purified by this method are suitable for cell-free reconstitution of essential mitochondrial processes and can be used for the analysis of mitochondrial structure and functions, mitochondrial proteome and lipidome, and mitochondrial DNA.

We describe a rapid and effective method for purification of mitochondria from the yeast Saccharomyces cerevisiae. This method enables the high-yield isolation of pure mitochondria that are essentially free of contamination by other organelles and retain their structural and functional integrity after their purification.

Mitochondria are the main site of ATP production during aerobic metabolism in eukaryotic non-photosynthetic cells1. These complex organelles also play ...

Isolation and Purification of Drosophila Peripheral Neurons by Magnetic Bead Sorting

The Drosophila peripheral nervous system (PNS) is a powerful model for investigating the complex processes of neuronal development and dendrite morphogenesis at the functional and molecular levels. To aid in these analyses, we have developed a strategy for the isolation of a subclass of PNS neurons called dendritic arborization (da) neurons that have been widely used for studying dendrite morphogenesis1,2. These neurons are very difficult to isolate as a pure population, due in part to their extremely low occurrence and their difficult-to-reach location below the tough chitinous larval cuticle. Our newly developed method overcomes these challenges, and is based on a fast and specific cell enrichment using antibody-coated magnetic beads. For our magnetic bead sorting studies, we have used age-matched third instar larvae expressing a mouse CD8 tagged GFP fusion protein (UAS-mCD8-GFP)3 under the control of either the class IV dendritic arborization (da) neuron-specific pickpocket (ppk)-GAL4 driver4 or the control of the pan-da neuron-specific GAL421-7 driver5. Although this protocol has been optimized for isolating PNS cells which are attached to the inner wall of the larval cuticle, by varying a few parameters, the same protocol could be used to isolate many different cell types attached to the cuticle at larval or pupal stages of development (e.g. epithelia, muscle, oenocytes etc.), or other cell types from larval organs depending upon the GAL4-specific driver expression pattern. The RNA isolated by this method is of high quality and can be readily used for downstream genomic analyses such as microarray gene expression profiling studies. This approach offers a powerful new tool to perform studies on isolated Drosophila dendritic arborization (da) neurons thereby providing novel insights into the molecular mechanisms underlying dendrite morphogenesis.

Isolation and Purification of Drosophila Peripheral Neurons by Magnetic Bead Sorting

In this video-article we present a method for the isolation and purification of Drosophila peripheral neurons using a fast magnetic bead assisted cell sorting strategy. RNA obtained from the isolated cells can be readily used for downstream applications including microarray analyses.

The Drosophila peripheral nervous system (PNS) is a powerful model for investigating the complex processes of neuronal development and dendrite ...

Isolation and Purification of Kinesin from Drosophila Embryos

Motor proteins move cargos along microtubules, and transport them to specific sub-cellular locations. Because altered transport is suggested to underlie a variety of neurodegenerative diseases, understanding microtubule based motor transport and its regulation will likely ultimately lead to improved therapeutic approaches. Kinesin-1 is a eukaryotic motor protein which moves in an anterograde (plus-end) direction along microtubules (MTs), powered by ATP hydrolysis. Here we report a detailed purification protocol to isolate active full length kinesin from Drosophila embryos, thus allowing the combination of Drosophila genetics with single-molecule biophysical studies. Starting with approximately 50 laying cups, with approximately 1000 females per cup, we carried out overnight collections. This provided approximately 10 ml of packed embryos. The embryos were bleach dechorionated (yielding approximately 9 grams of embryos), and then homogenized. After disruption, the homogenate was clarified using a low speed spin followed by a high speed centrifugation. The clarified supernatant was treated with GTP and taxol to polymerize MTs. Kinesin was immobilized on polymerized MTs by adding the ATP analog, 5'-adenylyl imidodiphosphate at room temperature. After kinesin binding, microtubules were sedimented via high speed centrifugation through a sucrose cushion. The microtubule pellet was then re-suspended, and this process was repeated. Finally, ATP was added to release the kinesin from the MTs. High speed centrifugation then spun down the MTs, leaving the kinesin in the supernatant. This kinesin was subjected to a centrifugal filtration using a 100 KD cut off filter for further purification, aliquoted, snap frozen in liquid nitrogen, and stored at -80 &deg;C. SDS gel electrophoresis and western blotting was performed using the purified sample. The motor activity of purified samples before and after the final centrifugal filtration step was evaluated using an in vitro single molecule microtubule assay. The kinesin fractions before and after the centrifugal filtration showed processivity as previously reported in literature. Further experiments are underway to evaluate the interaction between kinesin and other transport related proteins.

Isolation and Purification of Kinesin from Drosophila Embryos

This is a protocol to isolate active full length Kinesin from Drosophila embryos for single-molecule biophysical studies. We show how to collect embryos, make the embryo lysate, and then polymerize microtubules (MTs). Kinesin is purified by immobilizing it on the MTs, spinning down the Kinesin-MT complexes, and then releasing the kinesin from the MTs via ATP addition.

Motor proteins move cargos along microtubules, and transport them to specific sub-cellular locations. Because altered transport is suggested to underlie a ...

Chromatin Isolation by RNA Purification (ChIRP)

Long noncoding RNAs are key regulators of chromatin states for important biological processes such as dosage compensation, imprinting, and developmental gene expression 1,2,3,4,5,6,7. The recent discovery of thousands of lncRNAs in association with specific chromatin modification complexes, such as Polycomb Repressive Complex 2 (PRC2) that mediates histone H3 lysine 27 trimethylation (H3K27me3), suggests broad roles for numerous lncRNAs in managing chromatin states in a gene-specific fashion 8,9. While some lncRNAs are thought to work in cis on neighboring genes, other lncRNAs work in trans to regulate distantly located genes. For instance, Drosophila lncRNAs roX1 and roX2 bind numerous regions on the X chromosome of male cells, and are critical for dosage compensation 10,11. However, the exact locations of their binding sites are not known at high resolution. Similarly, human lncRNA HOTAIR can affect PRC2 occupancy on hundreds of genes genome-wide 3,12,13, but how specificity is achieved is unclear. LncRNAs can also serve as modular scaffolds to recruit the assembly of multiple protein complexes. The classic trans-acting RNA scaffold is the TERC RNA that serves as the template and scaffold for the telomerase complex 14; HOTAIR can also serve as a scaffold for PRC2 and a H3K4 demethylase complex 13.
Prior studies mapping RNA occupancy at chromatin have revealed substantial insights 15,16, but only at a single gene locus at a time. The occupancy sites of most lncRNAs are not known, and the roles of lncRNAs in chromatin regulation have been mostly inferred from the indirect effects of lncRNA perturbation. Just as chromatin immunoprecipitation followed by microarray or deep sequencing (ChIP-chip or ChIP-seq, respectively) has greatly improved our understanding of protein-DNA interactions on a genomic scale, here we illustrate a recently published strategy to map long RNA occupancy genome-wide at high resolution 17. This method, Chromatin Isolation by RNA Purification (ChIRP) (Figure 1), is based on affinity capture of target lncRNA:chromatin complex by tiling antisense-oligos, which then generates a map of genomic binding sites at a resolution of several hundred bases with high sensitivity and low background. ChIRP is applicable to many lncRNAs because the design of affinity-probes is straightforward given the RNA sequence and requires no knowledge of the RNA's structure or functional domains.

Chromatin Isolation by RNA Purification ChIRP

ChIRP is a novel and rapid technique to map genomic binding sites of long noncoding RNAs (lncRNAs). The method takes advantage of the specificity of anti-sense tiling oligonucleotides to allow the enumeration of lncRNA-bound genomic sites.

Long noncoding RNAs are key regulators of chromatin states for important biological processes such as dosage compensation, imprinting, and developmental ...

Planarian Immobilization, Partial Irradiation, and Tissue Transplantation

The planarian, a freshwater flatworm, has proven to be a powerful system for dissecting metazoan regeneration and stem cell biology1,2. Planarian regeneration of any missing or damaged tissues is made possible by adult stem cells termed neoblasts3. Although these stem cells have been definitively shown to be pluripotent and singularly capable of reconstituting an entire animal4, the heterogeneity within the stem cell population and the dynamics of their cellular behaviors remain largely unresolved. Due to the large number and wide distribution of stem cells throughout the planarian body plan, advanced methods for manipulating subpopulations of stem cells for molecular and functional study in vivo are needed.
Tissue transplantation and partial irradiation are two methods by which a subpopulation of planarian stem cells can be isolated for further study. Each technique has distinct advantages. Tissue transplantation allows for the introduction of stem cells, into a na&iuml;ve host, that are either inherently genetically distinct or have been previously treated pharmacologically. Alternatively, partial irradiation allows for the isolation of stem cells within a host, juxtaposed to tissue devoid of stem cells, without the introduction of a wound or any breech in tissue integrity. Using these two methods, one can investigate the cell autonomous and non-autonomous factors that control stem cell functions, such as proliferation, differentiation, and migration.
Both tissue transplantation5,6 and partial irradiation7 have been used historically in defining many of the questions about planarian regeneration that remain under study today. However, these techniques have remained underused due to the laborious and inconsistent nature of previous methods. The protocols presented here represent a large step forward in decreasing the time and effort necessary to reproducibly generate large numbers of grafted or partially irradiated animals with efficacies approaching 100 percent. We cover the culture of large animals, immobilization, preparation for partial irradiation, tissue transplantation, and the optimization of animal recovery. Furthermore, the work described here demonstrates the first application of the partial irradiation method for use with the most widely studied planarian, Schmidtea mediterranea. Additionally, efficient tissue grafting in planaria opens the door for the functional testing of subpopulations of na&iuml;ve or treated stem cells in repopulation assays, which has long been the gold-standard method of assaying adult stem cell potential in mammals8. Broad adoption of these techniques will no doubt lead to a better understanding of the cellular behaviors of adult stem cells during tissue homeostasis and regeneration.

An effective method for grafting tissue of defined and consistent size between planaria is described. Also included is a description of how the immobilization technique used for transplantation can be adapted, in conjunction with lead shields, for the partial irradiation of live animals.

The planarian, a freshwater flatworm, has proven to be a powerful system for dissecting metazoan regeneration and stem cell biology1,2. Planarian ...

Isolation, Culture, and Transplantation of Muscle Satellite Cells

Muscle satellite cells are a stem cell population required for postnatal skeletal muscle development and regeneration, accounting for 2-5% of sublaminal nuclei in muscle fibers. In adult muscle, satellite cells are normally mitotically quiescent. Following injury, however, satellite cells initiate cellular proliferation to produce myoblasts, their progenies, to mediate the regeneration of muscle. Transplantation of satellite cell-derived myoblasts has been widely studied as a possible therapy for several regenerative diseases including muscular dystrophy, heart failure, and urological dysfunction. Myoblast transplantation into dystrophic skeletal muscle, infarcted heart, and dysfunctioning urinary ducts has shown that engrafted myoblasts can differentiate into muscle fibers in the host tissues and display partial functional improvement in these diseases. Therefore, the development of efficient purification methods of quiescent satellite cells from skeletal muscle, as well as the establishment of satellite cell-derived myoblast cultures and transplantation methods for myoblasts, are essential for understanding the molecular mechanisms behind satellite cell self-renewal, activation, and differentiation. Additionally, the development of cell-based therapies for muscular dystrophy and other regenerative diseases are also dependent upon these factors.

However, current prospective purification methods of quiescent satellite cells require the use of expensive fluorescence-activated cell sorting (FACS) machines. Here, we present a new method for the rapid, economical, and reliable purification of quiescent satellite cells from adult mouse skeletal muscle by enzymatic dissociation followed by magnetic-activated cell sorting (MACS). Following isolation of pure quiescent satellite cells, these cells can be cultured to obtain large numbers of myoblasts after several passages. These freshly isolated quiescent satellite cells or ex vivo expanded myoblasts can be transplanted into cardiotoxin (CTX)-induced regenerating mouse skeletal muscle to examine the contribution of donor-derived cells to regenerating muscle fibers, as well as to satellite cell compartments for the examination of self-renewal activities.

The isolation and culture of a pure population of quiescent satellite cells, a muscle stem cell population, is essential to the understanding of muscle stem cell biology and regeneration, as well as stem cell transplantation for therapies in muscular dystrophy and other degenerative diseases.&#160;

Muscle satellite cells are a stem cell population required for postnatal skeletal muscle development and regeneration, accounting for 2-5% of sublaminal ...

Isolation and Functional Analysis of Mitochondria from Cultured Cells and Mouse Tissue

Comparison between two or more distinct groups, such as healthy vs. disease, is necessary to determine cellular status. Mitochondria are at the nexus of cell heath due to their role in both cell metabolism and energy production as well as control of apoptosis. Therefore, direct evaluation of isolated mitochondria and mitochondrial perturbation offers the ability to determine if organelle-specific (dys)function is occurring. The methods described in this protocol include isolation of intact, functional mitochondria from HEK cultured cells and mouse liver and spinal cord, but can be easily adapted for use with other cultured cells or animal tissues. Mitochondrial function assessed by TMRE and the use of common mitochondrial uncouplers and inhibitors in conjunction with a fluorescent plate reader allow this protocol not only to be versatile and accessible to most research laboratories, but also offers high throughput.

Comparison of mitochondrial membrane potential between samples yields valuable information about cellular status. Detailed steps for isolating mitochondria and assessing response to inhibitors and uncouplers using fluorescence are described. The method and utility of this protocol are illustrated by use of a cell culture and animal model of cellular stress.

Comparison between two or more distinct groups, such as healthy vs. disease, is necessary to determine cellular status. Mitochondria are at the nexus of ...

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.

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