Name: identification and analysis of mouse erythroid progenitors using the cd71/ter119 flow-cytometric assay
Uploaded: 2011-08-05T13:00:00
Description: Watch this Scientific Journal Video about Identification and Analysis of Mouse Erythroid Progenitors using the CD71/TER119 Flow-cytometric Assay at JoVE.com

We thank the UMass flow cytometry core: Richard Konz, Ted Giehl, Barbara Gosselin, Yuehua Gu and Tammy Krupoch. This work was funded by NIH/NHLBI RO1 HL084168 (M.S.) and NIH CA T32-130807 (J.R.S.). Core resources supported by the Diabetes Endocrinology Research Center grant DK32520 were also used.

1. Harvesting of tissues
<ol>
<li>Prepare tubes containing 2 to 5 ml cold staining buffer (phosphate-buffered saline (PBS) with added 0.2% BSA and 5mM glucose). Keep tubes on ice prior to tissue harvest. </li>
<li>Cull mice according to appropriate approved protocol (e.g. CO2 inhalation followed by cervical dislocation).</li>
<li>Draw blood by cardiac puncture into EDTA or heparin blood-collection tubes for later analysis, e.g. of hematocrit, reticulocyte count or CBC analysis.</li>
<li>Harvest the spleen an...

<ol>
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The flow-cytometric methodology allows simultaneous investigation of any cellular function that may be detected with a fluorescence-conjugated specific antibody or ligand, including cell surface markers, protein expression, cell survival, cell signaling using phospho-specific antibodies 3 and cell cycle status. These measurements may be made in each of a number of differentiation-stage specific subsets, in the context of freshly isolated erythropoietic tissue. This method therefore allows assessment of functio...

<table border="1">
 <tbody>
 <tr>
 <th>Name of the reagent</th>
 <th>Company</th>
 <th>Catalogue number</th>
 </tr>
 <tr>
	<td>Fas-biotin</td>
	<td>BD Pharmingen</td>
	<td>554256</td>
 </tr>
 <tr>
	<td>Streptavidin-APC</td>
	<td>Molecular Probes</td>
	<td>S868</td>
 </tr>
 <tr>
 <td>40 &mu;m sterile cell strainer </td>
 <td>Fisherbrand</td>
 <td>22363547</td>
 </tr>
 <tr>
 <td>Polystyrene round-bottom tubes for FACS staining </td>
 <td>BD Falcon</td>
 <td>352008</td>
 </tr>
 <tr>
 <td>U-bottom 96 well plate </td>
 <td>BD Falcon</td>
 <td>353910</td>
 </tr>
 <tr>
 <td>ChromePure Rabbit IgG</td>
 <td>Jackson ImmunoResearch</td>
 <td>015-000-003</td>
 </tr>
 <tr>
 <td>CD71-FITC (stock 0.5mg/ml)</td>
 <td>BD-Biosciences</td>
 <td>553266</td>
 </tr>
 <tr>
 <td>Ter119-PE (stock 0.2mg/ml) </td>
 <td>BD-Biosciences</td>
 <td>553673</td>
 </tr>
 <tr>
 <td>7AAD </td>
 <td>BD-Biosciences</td>
 <td>559925</td>
 </tr>
 <tr>
 <td>DAPI powder </td>
 <td>Roche</td>
 <td>236276</td>
 </tr>
 <tr>
 <td>FITC Rat Anti-Mouse CD41 MWReg30</td>
 <td>BD Pharmingen </td>
 <td>553848</td>
 </tr>
 <tr>
 <td>FITC Rat Anti-Mouse CD45R/B220 RA3-6B2</td>
 <td>BD Pharmingen </td>
 <td>553087</td>
 </tr>
 <tr>
 <td>FITC Rat Anti-Mouse CD411b/Mac-1 M1/70</td>
 <td>BD Pharmingen </td>
 <td>557396</td>
 </tr>
 <tr>
 <td>FITC Rat Anti-Mouse Ly-6G and Ly-6C (Gr-1) RB6-8C5</td>
 <td>BD Pharmingen </td>
 <td>553126</td>
 </tr>
 <tr>
 <td>FITC Hamster Anti-Mouse CD3e 145-2C11 </td>
 <td>BD Pharmingen </td>
 <td>553061</td>
 </tr>
 <tr>
 <td>APC BrdU Flow kit</td>
 <td>BD Pharmingen</td>
 <td>557892</td>
 </tr>
 <tr>
 <td>Annexin V-biotin</td>
 <td>BD Pharmingen</td>
 <td>556418</td>
 </tr>
 </tbody>
</table>

identification and analysis of mouse erythroid progenitors using the cd71/ter119 flow-cytometric assay

The study of erythropoiesis aims to understand how red cells are formed from earlier hematopoietic and erythroid progenitors. Specifically, the rate of red cell formation is regulated by the hormone erythropoietin (Epo), whose synthesis is triggered by tissue hypoxia. A threat to adequate tissue oxygenation results in a rapid increase in Epo, driving an increase in erythropoietic rate, a process known as the erythropoietic stress response. The resulting increase in the number of circulating red cells improves tissue oxygen delivery. An efficient erythropoietic stress response is therefore critical to the survival and recovery from physiological and pathological conditions such as high altitude, anemia, hemorrhage, chemotherapy or stem cell transplantation. 
The mouse is a key model for the study of erythropoiesis and its stress response. Mouse definitive (adult-type) erythropoiesis takes place in the fetal liver between embryonic days 12.5 and 15.5, in the neonatal spleen, and in adult spleen and bone marrow. Classical methods of identifying erythroid progenitors in tissue rely on the ability of these cells to give rise to red cell colonies when plated in Epo-containing semi-solid media. Their erythroid precursor progeny are identified based on morphological criteria. Neither of these classical methods allow access to large numbers of differentiation-stage-specific erythroid cells for molecular study. Here we present a flow-cytometric method of identifying and studying differentiation-stage-specific erythroid progenitors and precursors, directly in the context of freshly isolated mouse tissue. The assay relies on the cell-surface markers CD71, Ter119, and on the flow-cytometric 'forward-scatter' parameter, which is a function of cell size. The CD71/Ter119 assay can be used to study erythroid progenitors during their response to erythropoietic stress in vivo, for example, in anemic mice or mice housed in low oxygen conditions. It may also be used to study erythroid progenitors directly in the tissues of genetically modified adult mice or embryos, in order to assess the specific role of the modified molecular pathway in erythropoiesis.

Watch this Scientific Journal Video about Identification and Analysis of Mouse Erythroid Progenitors using the CD71/TER119 Flow-cytometric Assay at JoVE.com

Identification and Analysis of Mouse Erythroid Progenitors using the CD71/TER119 Flow-cytometric Assay

A flow-cytometric method for identification and molecular analysis of differentiation-stage-specific murine erythroid progenitors and precursors, directly in freshly &#x2013;harvested mouse bone marrow, spleen or fetal liver. The assay relies on cell-surface markers CD71, Ter119, and cell size.

The study of erythropoiesis aims to understand how red cells are formed from earlier hematopoietic and erythroid progenitors. Specifically, the rate of ...

identification-analysis-mouse-erythroid-progenitors-using-cd71ter119

Research

JoVE Journal

Biology

A Quantitative Assay for Insulin-expressing Colony-forming Progenitors

The field of pancreatic stem and progenitor cell biology has been hampered by a lack of in vitro functional and quantitative assays that allow for the analysis of the single cell. Analyses of single progenitors are of critical importance because they provide definitive ways to unequivocally demonstrate the lineage potential of individual progenitors. Although methods have been devised to generate "pancreatospheres" in suspension culture from single cells, several limitations exist. First, it is time-consuming to perform single cell deposition for a large number of cells, which in turn commands large volumes of culture media and space. Second, numeration of the resulting pancreatospheres is labor-intensive, especially when the frequency of the pancreatosphere-initiating progenitors is low. Third, the pancreatosphere assay is not an efficient method to allow both the proliferation and differentiation of pancreatic progenitors in the same culture well, restricting the usefulness of the assay.
To overcome these limitations, a semi-solid media based colony assay for pancreatic progenitors has been developed and is presented in this report. This method takes advantage of an existing concept from the hematopoietic colony assay, in which methylcellulose is used to provide viscosity to the media, allowing the progenitor cells to stay in three-dimensional space as they undergo proliferation as well as differentiation. To enrich insulin-expressing colony-forming progenitors from a heterogeneous population, we utilized cells that express neurogenin (Ngn) 3, a pancreatic endocrine progenitor cell marker. Murine embryonic stem (ES) cell-derived Ngn3 expressing cells tagged with the enhanced green fluorescent protein reporter were sorted and as many as 25,000 cells per well were plated into low-attachment 24-well culture dishes. Each well contained 500 &mu;L of semi-solid media with the following major components: methylcellulose, Matrigel, nicotinamide, exendin-4, activin &beta;B, and conditioned media collected from murine ES cell-derived pancreatic-like cells. After 8 to 12 days of culture, insulin-expressing colonies with distinctive morphology were formed and could be further analyzed for pancreatic gene expression using quantitative RT-PCR and immunoflourescent staining to determine the lineage composition of each colony.
In summary, our colony assay allows easy detection and quantification of functional progenitors within a heterogeneous population of cells. In addition, the semi-solid media format allows uniform presentation of extracellular matrix components and growth factors to cells, enabling progenitors to proliferate and differentiate in vitro. This colony assay provides unique opportunities for mechanistic studies of pancreatic progenitor cells at the single cell level.

A three-dimensional clonogenic assay that allows pancreatic-like progenitors to differentiate into insulin-expressing colonies is described. This method takes advantage of semi-solid media containing methylcellulose, Matrigel and growth factors, in which single progenitors proliferate and differentiate in vitro, permitting quantification of the number of functional progenitors in a population.

The field of pancreatic stem and progenitor cell biology has been hampered by a lack of in vitro functional and quantitative assays that allow for the ...

SA-&#946;-Galactosidase-Based Screening Assay for the Identification of Senotherapeutic Drugs

Cell senescence is one of the hallmarks of aging known to negatively influence a healthy lifespan. Drugs able to kill senescent cells specifically in cell culture, termed senolytics, can reduce the senescent cell burden in vivo and extend healthspan. Multiple classes of senolytics have been identified to date including HSP90 inhibitors, Bcl-2 family inhibitors, piperlongumine, a FOXO4 inhibitory peptide and the combination of Dasatinib/Quercetin. Detection of SA-&#946;-Gal at an increased lysosomal pH is one of the best characterized markers for the detection of senescent cells. Live cell measurements of senescence-associated &#946;-galactosidase (SA-&#946;-Gal) activity using the fluorescent substrate C12FDG in combination with the determination of the total cell number using a DNA intercalating Hoechst dye opens the possibility to screen for senotherapeutic drugs that either reduce overall SA-&#946;-Gal activity by killing of senescent cells (senolytics) or by suppressing SA-&#946;-Gal and other phenotypes of senescent cells (senomorphics). Use of a high content fluorescent image acquisition and analysis platform allows for the rapid, high throughput screening of drug libraries for effects on SA-&#946;-Gal, cell morphology and cell number.

SA-&amp;#946;-Galactosidase-Based Screening Assay for the Identification of Senotherapeutic Drugs

Cellular senescence is the key factor in the development of chronic age-related pathologies. Identification of therapeutics that target senescent cells show promise for extending healthy aging. Here, we present a novel assay to screen for the identification of senotherapeutics based on measurement of senescence associated &#946;-Galactosidase activity in single cells.

Cell senescence is one of the hallmarks of aging known to negatively influence a healthy lifespan. Drugs able to kill senescent cells specifically in cell ...

Flow Cytometric Analysis of Extracellular Vesicles from Cell-conditioned Media

Flow cytometry (FC) is the method of choice for semi-quantitative measurement of cell-surface antigen markers. Recently, this technique has been used for phenotypic analyses of extracellular vesicles (EV) including exosomes (Exo) in the peripheral blood and other body fluids. The small size of EV mandates the use of dedicated instruments having a detection threshold around 50-100 nm. Alternatively, EV can be bound to latex microbeads that can be detected by FC. Microbeads, conjugated with antibodies that recognize EV-associated markers/Cluster of Differentiation CD63, CD9, and CD81 can be used for EV capture. Exo isolated from CM can be analyzed with or without pre-enrichment by ultracentrifugation. This approach is suitable for EV analyses using conventional FC instruments. Our results demonstrate a linear correlation between Mean Fluorescence Intensity (MFI) values and EV concentration. Disrupting EV through sonication dramatically decreased MFI, indicating that the method does not detect membrane debris. We report an accurate and reliable method for the analysis of EV surface antigens, which can be easily implemented in any laboratory.

The protocol describes a reproducible method designed for use with cell culture supernatants to detect surface epitopes on small extracellular vesicles (EV). It utilizes specific EV immunoprecipitation using beads coupled with antibodies that recognize surface antigen CD9, CD63, and CD81. The method is optimized for downstream flow cytometry analysis.

Flow cytometry (FC) is the method of choice for semi-quantitative measurement of cell-surface antigen markers. Recently, this technique has been used for ...

Identification, Isolation, and Characterization of Fibro-Adipogenic Progenitors (FAPs) and Myogenic Progenitors (MPs) in Skeletal Muscle in the Rat

Fibro-adipogenic Progenitors (FAPs) are resident interstitial cells in skeletal muscle that, together with myogenic progenitors (MPs), play a key role in muscle homeostasis, injury, and repair. Current protocols for FAPs identification and isolation use flow cytometry/fluorescence-activated cell sorting (FACS) and studies evaluating their function in vivo to date have been undertaken exclusively in mice. The larger inherent size of the rat allows for a more comprehensive analysis of FAPs in skeletal muscle injury models, especially in severely atrophic muscle or when investigators require substantial tissue mass to conduct multiple downstream assays. The rat additionally provides a larger selection of muscle functional assays that do not require animal sedation or sacrifice, thus minimizing morbidity and animal use by enabling serial assessments. The flow cytometry/FACS protocols optimized for mice are species specific, notably restricted by the characteristics of commercially available antibodies. They have not been optimized for separating FAPs from rat or highly fibrotic muscle. A flow cytometry/FACS protocol for the identification and isolation of FAPs and MPs from both healthy and denervated rat skeletal muscle was developed, relying on the differential expression of surface markers CD31, CD45, Sca-1, and VCAM-1. As rat-specific, flow cytometry-validated primary antibodies are severely limited, in-house conjugation of the antibody targeting Sca-1 was performed. Using this protocol, successful Sca-1 conjugation was confirmed, and flow cytometric identification of FAPs and MPs was validated by cell culture and immunostaining of FACS-isolated FAPs and MPs. Finally, we report a novel FAPs time-course in a prolonged (14 week) rat denervation model. This method provides the investigators the ability to study FAPs in a novel animal model.

Identification, Isolation, and Characterization of Fibro-Adipogenic Progenitors FAPs and Myogenic Progenitors MPs in Skeletal Muscle in the Rat

This protocol outlines a method to isolate Fibro-adipogenic progenitors (FAPs) and myogenic progenitors (MPs) from rat skeletal muscle. Utilization of the rat in muscle injury models provides increased tissue availability from atrophic muscle for the analysis and a larger repertoire of validated methods to assess muscle strength and gait in free-moving animals.

Fibro-adipogenic Progenitors (FAPs) are resident interstitial cells in skeletal muscle that, together with myogenic progenitors (MPs), play a key role in ...

Isolation of Mouse Megakaryocyte Progenitors

Bone marrow megakaryocytes are large polyploid cells that ensure the production of blood platelets. They arise from hematopoietic stem cells through megakaryopoiesis. The final stages of this process are complex and classically involve the bipotent Megakaryocyte-Erythrocyte Progenitors (MEP) and the unipotent Megakaryocyte Progenitors (MKp). These populations precede the formation of bona fide megakaryocytes and, as such, their isolation and characterization could allow for the robust and unbiased analysis of megakaryocyte formation. This protocol presents in detail the procedure to collect hematopoietic cells from mouse bone marrow, the enrichment of hematopoietic progenitors through magnetic depletion and finally a cell sorting strategy that yield highly purified MEP and MKp populations. First, bone marrow cells are collected from the femur, the tibia, and also the iliac crest, a bone that contains a high number of hematopoietic progenitors. The use of iliac crest bones drastically increases the total cell number obtained per mouse and thus contributes to a more ethical use of animals. A magnetic lineage depletion was optimized using 450 nm magnetic beads allowing a very efficient cell sorting by flow cytometry. Finally, the protocol presents the labeling and gating strategy for the sorting of the two highly purified megakaryocyte progenitor populations: MEP (Lin-Sca-1-c-Kit+CD16/32-CD150+CD9dim) and MKp (Lin- Sca-1-c-Kit+CD16/32-CD150+CD9bright). This technique is easy to implement and provides enough cellular material to perform i) molecular characterization for a deeper knowledge of their identity and biology, ii) in vitro differentiation assays, that will provide a better understanding of the mechanisms of maturation of megakaryocytes, or iii) in vitro models of interaction with their microenvironment.

This method describes the purification by flow cytometry of MEP and MKp from mice femurs, tibias, and pelvic bones.

Bone marrow megakaryocytes are large polyploid cells that ensure the production of blood platelets. They arise from hematopoietic stem cells through ...

Quantitative Analysis of Mitophagy in Murine Pancreatic &amp;#946;-Cells

Complementary Approaches to Interrogate Mitophagy Flux in Pancreatic &#946;-Cells

Mitophagy is a quality control mechanism necessary to maintain optimal mitochondrial function. Dysfunctional &#946;-cell mitophagy results in insufficient insulin release. Advanced quantitative assessments of mitophagy often require the use of genetic reporters. The mt-Keima mouse model, which expresses a mitochondria-targeted pH-sensitive dual-excitation ratiometric probe for quantifying mitophagy via flow cytometry, has been optimized in &#946;-cells. The ratio of acidic-to-neutral mt-Keima wavelength emissions can be used to robustly quantify mitophagy. However, using genetic mitophagy reporters can be challenging when working with complex genetic mouse models or difficult-to-transfect cells, such as primary human islets. This protocol describes a novel complementary dye-based method to quantify &#946;-cell mitophagy in primary islets using MtPhagy. MtPhagy is a pH-sensitive, cell-permeable dye that accumulates in the mitochondria and increases its fluorescence intensity when mitochondria are in low pH environments, such as lysosomes during mitophagy. By combining the MtPhagy dye with Fluozin-3-AM, a Zn2+ indicator that selects for &#946;-cells, and Tetramethylrhodamine, ethyl ester (TMRE) to assess mitochondrial membrane potential, mitophagy flux can be quantified specifically in &#946;-cells via flow cytometry. These two approaches are highly complementary, allowing for flexibility and precision in assessing mitochondrial quality control in numerous &#946;-cell models.

Author Spotlight: Assessment of Mitophagy Flux in Pancreatic &amp;#946;-Cells Using Effective and Robust Complementary Approaches 

This protocol outlines two methods for the quantitative analysis of mitophagy in pancreatic &#946;-cells: first, a combination of cell-permeable mitochondria-specific dyes, and second, a genetically encoded mitophagy reporter. These two techniques are complementary and can be deployed based on specific needs, allowing for flexibility and precision in quantitatively addressing mitochondrial quality control.

Mitophagy is a quality control mechanism necessary to maintain optimal mitochondrial function. Dysfunctional &#946;-cell mitophagy results in insufficient ...

Quantitative Analysis of Microbial Autoaggregation Using Imaging Flow Cytometry

Imaging Flow Cytometry to Study Microbial Autoaggregation

Beneficial and probiotic bacteria play essential roles in their hosts, providing various health benefits, including immunity to infectious diseases. The Lactobacillaceae family consists of Gram-positive bacteria with confirmed probiotic properties. This study utilizes Lactobacillaceae species as a model to demonstrate the effectiveness of single-cell high throughput analysis in studying cellular aggregation. The focus is on analyzing the response of these beneficial species to simple carbohydrates from the diet.
The study showcases how Imaging Flow Cytometry (IFC) can overcome the fundamental differences in the assembly of probiotic bacteria in the presence and absence of carbohydrates. IFC combines the power and speed of conventional flow cytometry with the spatial resolution of microscopy, enabling high-rate complex morphometric measurements in a phenotypically defined manner across a library of beneficial bacterial strains and conditions. This protocol provides insights into the autoaggregation of Lactobacillaceae species and sheds light on their response to dietary carbohydrates, contributing to understanding the mechanisms behind the beneficial effects of these probiotic bacteria.

Author Spotlight: Advancing Research in Microbial Autoaggregation Using Imaging Flow Cytometry

This protocol describes a quantitative approach to measure microbial autoaggregation using imaging flow cytometry.

Beneficial and probiotic bacteria play essential roles in their hosts, providing various health benefits, including immunity to infectious diseases. The ...

Single-Cell CyTOF Analysis of Myogenic Progenitors in Muscle Regeneration

Identification and Analysis of Myogenic Progenitors In Vivo During Acute Skeletal Muscle Injury by High-Dimensional Single-Cell Mass Cytometry

Skeletal muscle regeneration is a dynamic process driven by adult muscle stem cells and their progeny. Mostly quiescent at a steady state, adult muscle stem cells become activated upon muscle injury. Following activation, they proliferate, and most of their progeny differentiate to generate fusion-competent muscle cells while the remaining self-renews to replenish the stem cell pool. While the identity of muscle stem cells was defined more than a decade ago, based on the co-expression of cell surface markers, myogenic progenitors were identified only recently using high-dimensional single-cell approaches. Here, we present a single-cell mass cytometry (cytometry by time of flight [CyTOF]) method to analyze stem cells and progenitor cells in acute muscle injury to resolve the cellular and molecular dynamics that unfold during muscle regeneration. This approach is based on the simultaneous detection of novel cell surface markers and key myogenic transcription factors whose dynamic expression enables the identification of activated stem cells and progenitor cell populations that represent landmarks of myogenesis. Importantly, a sorting strategy based on detecting cell surface markers CD9 and CD104 is described, enabling prospective isolation of muscle stem and progenitor cells using fluorescence-activated cell sorting (FACS) for in-depth studies of their function. Muscle progenitor cells provide a critical missing link to study the control of muscle stem cell fate, identify novel therapeutic targets for muscle diseases, and develop cell therapy applications for regenerative medicine. The approach presented here can be applied to study muscle stem and progenitor cells in vivo in response to perturbations, such as pharmacological interventions targeting specific signaling pathways. It can also be used to investigate the dynamics of muscle stem and progenitor cells in animal models of muscle diseases, advancing our understanding of stem cell diseases and accelerating the development of therapies.

Author Spotlight: Investigating Cellular and Molecular Dynamics During Muscle Regeneration Using Cutting-Edge Single-Cell Technologies

The protocol presented here enables the identification and high-dimensional analysis of muscle stem and progenitor cells by single-cell mass cytometry and their purification by FACS for in-depth studies of their function. This approach can be applied to study regeneration dynamics in disease models and test the efficacy of pharmacological interventions.

Skeletal muscle regeneration is a dynamic process driven by adult muscle stem cells and their progeny. Mostly quiescent at a steady state, adult muscle ...

Mesenchymal Stem Cell Sample Preparation, Flow Cytometric Analysis, and Cell Sorting

To begin, label two new fax tubes as mixed tubes one and two. Prepare the cell and antibody suspension as per the given table for flow cytometric analysis. After incubating the tubes for 30 minutes, wash each tube two times with one milliliter of staining buffer.Centrifuge the vortexed tubes at 200 G for 10 minutes at room temperature. Then re-suspend the pellet in 500 microliters of staining buffer. Coat the wells of a 48 well plate with 200 to 500 microliters of FBS, and keep for one hour.Then pipette 200 to 500 microliters of 10%MSC media after removing the residual FBS. To prepare the samples for single cell sorting, pipette one milliliter of FBS into two new fax tubes. Roll the tubes to create an even coat of the FBS on the tube's inner surface.Prepare the cell and antibody suspension in mixed tubes one and two, as per the table, for the sorting experiment. Then incubate the tubes in the dark for 30 minutes at room temperature. After washing with staining buffer, centrifuge the tubes at 200 G for 10 minutes at room temperature.Then re-suspend the pellet in 500 microliters of staining buffer and incubate for 15 minutes in five microliters of DAPI before sorting. To set up the compensation matrix, use the single stain compensation tubes. Click on experiment from the toolbar in the instrument software.Then click on compensation setup, followed by create compensation controls. Next, click on unstained tube, followed by parameters in the cytometer dialogue box. Adjust the voltages by editing the values for each parameter.Click on load in the acquisition dashboard and then click acquire. Drag the P-1 gate to the cell population and apply it across all compensation controls to set the voltage and negative gate for each parameter. Now load the single stain compensation tubes individually.Record the data and save it. Select the current experiment, right click on it, and select calculate compensation values, followed by link and save. Run the mixed tube one and record 10, 000 cells.Set the gates on the population of interest to be sorted with the proper gating strategy. Next, load a collection plate into the instrument and set a target cell number, ranging from 2, 500 to 5, 000 cells per well. Then select the single cell sort purity mask.Collect the sorted cell populations in a collection device, keeping them on ice for the duration of the sorting experiment. Finally, shift the plates into a 5%carbon dioxide incubator to maintain the cultures at 37 degrees Celsius. The multi-parametric flow cytometry assays plots showed no expression of the FITC isotype of CD 90 FITC antibodies.Positive expression of the markers CD-90 and CD-73 and negative expression of CD-45 are comparable with that of their unstained and FMO controls. The immuno phenotypes showed the marker distribution from one of the early passages with the ISCT recommended markers and CD-44, determining the parent populations as MSCs. The late passage sheds were used for single cell sorting of high and dim expressors.The post sorted cells collected in the 48 well plate showed adherence and proliferation, like their parent population. The post sorted cells differentiated in the presence of adipogenic growth factors.

Single-Cell Dissociation of Murine Islets for Flow Cytometric Analysis of &#946;-Cell Mitophagy

Begin by culturing the eyelet samples isolated from regular fat diet or high fat diet mice overnight at 37 degrees Celsius. Design the desired experimental conditions for the study. For each experimental condition, using a pipette, pick 100 eyelets into a six centimeter Petri dish containing two milliliters of eyelet medium.To induce Mitophagy, treat the eyelets in the appropriate Petri dishes with two microliters of 250 nano molar Valinomycin stock for three hours. Isolate the eyelets and using a pipette, transfer the eyelets from each Petri dish to a separate micro centrifuge tube. Then, spin the eyelets at 350 G for one minute at 10 degrees Celsius and using a pipette, discard the supernatant.Wash the obtained sample twice with one milliliter of PBS. Between the washes, spin the sample and discard the supernatant as demonstrated previously. To dissociate eyelets into single cells, add 500 microliters of 0.05%Trypsin prewarmed to 37 degrees celsius, to one sample tube.Pipette the contents of the tube up and down repeatedly until the eyelets are visibly dispersed. Immediately add one milliliter of prewarmed eyelet medium to neutralize trypsin. Spin the samples at 500 G for five minutes at 10 degrees Celsius.Remove the supernatant carefully without disturbing the pellet. Then, wash the samples two times with eyelet flow medium. The cell samples are now ready to be stained for flow cytometric analysis of beta cell mitophagy.