感谢MilliporeSigma的同事Philip J. Morrissey和Sherree L. Friend对他们多年来的支持和指导。我还要感谢Vidya Venkatachalam和Bryan R. Davidson在IDEAS软件中的BDC3功能的帮助， Ryan P. Jessup帮助编辑这本手稿，Raymond Kong在拍摄当天的帮助，特别感谢化妆师辛西娅Xamonthiene。

<ol>
	<li>Levine, B., Klionsky, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+by+self-digestion:+molecular+mechanisms+and+biological+functions+of+autophagy.">Development by self-digestion: molecular mechanisms and biological functions of autophagy.</a> Developmental Cell. 6, 463-477 (2004).</li><li>Zhang, X. J., Chen, S., Huang, K. X., Le, W. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Why+should+autophagic+flux+be+assessed?.">Why should autophagic flux be assessed?.</a> Acta Pharmacologica Sinica. 34, 595-599 (2013).</li><li>Tanida, I., Takashi, U., Kominami, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=LC3+and+Autophagy.">LC3 and Autophagy.</a> Methods Mol Biol. 445, 77-88 (2008).</li><li>Larsen, K. B., Lamark, T., &#216;vervatn, A., Harneshaug, I., Johansen, T., Bj&#248;rk&#248;y, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+reporter+cell+system+to+monitor+autophagy+based+on+p62/SQSTM1.">A reporter cell system to monitor autophagy based on p62/SQSTM1.</a> Autophagy. 6 (6), 784-793 (2010).</li><li>Demishtein, A., Porat, Z., Elazar, Z., Shvets, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Applications+of+flow+cytometry+for+measurement+of+autophagy.">Applications of flow cytometry for measurement of autophagy.</a> Methods. 75, 87-95 (2015).</li><li>Mizushima, N., Yoshimori, T., Levine, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Methods+in+mammalian+autophagy+research.">Methods in mammalian autophagy research.</a> Cell. 140 (3), 313-326 (2010).</li><li>Klionsky, D. J., 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=Guidelines+for+the+use+and+interpretation+of+assays+for+monitoring+autophagy.">Guidelines for the use and interpretation of assays for monitoring autophagy.</a> Autophagy. 8 (4), 445-544 (2012).</li><li>Arsov, I., 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=BAC-mediated+transgenic+expression+of+fluorescent+autophagic+protein+Beclin+1+reveals+a+role+for+Beclin+1+in+lymphocyte+development.">BAC-mediated transgenic expression of fluorescent autophagic protein Beclin 1 reveals a role for Beclin 1 in lymphocyte development.</a> Cell Death Differ. 15 (9), 1385-1395 (2008).</li><li>Maloyan, A., Sayegh, J., Osinska, H., Chua, B. H., Robbins, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Manipulation+of+death+pathways+in+desmin-related+cardiomyopathy.">Manipulation of death pathways in desmin-related cardiomyopathy.</a> Circ Res. 106 (9), 1524-1532 (2010).</li><li>Altman, B. J., 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=Autophagy+is+essential+to+suppress+cell+stress+and+to+allow+BCR-Abl-mediated+leukemogenesis.">Autophagy is essential to suppress cell stress and to allow BCR-Abl-mediated leukemogenesis.</a> Oncogene. 30 (16), 1855-1867 (2011).</li><li>Suarez, A. L., Kong, R., George, T., He, L., Yue, Z., van Dyk, L. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gammaherpesvirus+68+infection+of+endothelial+cells+requires+both+host+autophagy+genes+and+viral+oncogenes+for+optimal+survival+and+persistence.">Gammaherpesvirus 68 infection of endothelial cells requires both host autophagy genes and viral oncogenes for optimal survival and persistence.</a> J Virol. 85 (13), 6293-6308 (2011).</li><li>Tra, T., 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=Autophagy+in+human+embryonic+stem+cells.">Autophagy in human embryonic stem cells.</a> PLoS One. 6 (11), (2011).</li><li>Yuan, N., 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=Bafilomycin+A1+targets+both+autophagy+and+apoptosis+pathways+in+pediatric+B-cell+acute+lymphoblastic+leukemia.">Bafilomycin A1 targets both autophagy and apoptosis pathways in pediatric B-cell acute lymphoblastic leukemia.</a> Haematologica. 100 (3), 345-356 (2015).</li><li>Leveque-El Mouttie, L., 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=Autophagy+is+required+for+stem+cell+mobilization+by+G-CSF.">Autophagy is required for stem cell mobilization by G-CSF.</a> Blood. 125 (19), 2933-2936 (2015).</li><li>Watson, A. 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=Autophagy+limits+proliferation+and+glycolytic+metabolism+in+acute+myeloid+leukemia.">Autophagy limits proliferation and glycolytic metabolism in acute myeloid leukemia.</a> Cell Death Discov. 1, 15008 (2015).</li><li>Stranks, A. J., 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=Autophagy+Controls+Acquisition+of+Aging+Features+in+Macrophages.">Autophagy Controls Acquisition of Aging Features in Macrophages.</a> J Innate Immun. 7 (4), 375-391 (2015).</li><li>Clarke, A. J., 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=Autophagy+is+activated+in+systemic+lupus+erythematosus+and+required+for+plasmablast+development.">Autophagy is activated in systemic lupus erythematosus and required for plasmablast development.</a> Ann Rheum Dis. 74 (5), 912-920 (2015).</li><li>Warnes, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Flow+cytometric+assays+for+the+study+of+autophagy.">Flow cytometric assays for the study of autophagy.</a> Methods. 82, 21-28 (2015).</li><li>Bj&#248;rk&#248;y, G., 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=p62/SQSTM1+forms+protein+aggregates+degraded+by+autophagy+and+has+a+protective+effect+on+huntingtin-induced+cell+death.">p62/SQSTM1 forms protein aggregates degraded by autophagy and has a protective effect on huntingtin-induced cell death.</a> J Cell Biol. 171 (4), 603-614 (2005).</li><li>Phadwal, K., 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+novel+method+for+autophagy+detection+in+primary+cells:+Impaired+levels+of+macroautophagy+in+immunosenescent+T+cells.">A novel method for autophagy detection in primary cells: Impaired levels of macroautophagy in immunosenescent T cells.</a> Autophagy. 8 (4), 677-689 (2012).</li><li>Rajan, R., Karbowniczek, M., Pugsley, H. R., Sabnani, M. K., Astrinidis, A., La-Beck, 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=Quantifying+autophagosomes+and+autolysosomes+in+cells+using+imaging+flow+cytometry.">Quantifying autophagosomes and autolysosomes in cells using imaging flow cytometry.</a> Cytometry A. 87 (5), 451-458 (2015).</li><li>Kwok, A. 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=HspB8+mutation+causing+hereditary+distal+motor+neuropathy+impairs+lysosomal+delivery+of+autophagosomes.">HspB8 mutation causing hereditary distal motor neuropathy impairs lysosomal delivery of autophagosomes.</a> J Neurochem. 119 (6), 1155-1161 (2011).</li><li>Lopez-Herrera, G., 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=Deleterious+Mutations+in+LRBA+Are+Associated+with+a+Syndrome+of+Immune+Deficiency+and+Autoimmunity.">Deleterious Mutations in LRBA Are Associated with a Syndrome of Immune Deficiency and Autoimmunity.</a> Am J Hum Genet. 90 (6), 986-1001 (2012).</li><li>Pike, L. R., Phadwal, K., Simon, A. K., Harris, A. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=ATF4+orchestrates+a+program+of+BH3-only+protein+expression+in+severe+hypoxia.">ATF4 orchestrates a program of BH3-only protein expression in severe hypoxia.</a> Mol Biol Rep. 39 (12), 10811-10822 (2012).</li><li>Pike, L. R., 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=Transcriptional+up-regulation+of+ULK1+by+ATF4+contributes+to+cancer+cell+survival.">Transcriptional up-regulation of ULK1 by ATF4 contributes to cancer cell survival.</a> Biochem J. 449 (2), 389-400 (2013).</li><li>Pugsley, H. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantifying+autophagy:+Measuring+LC3+puncta+and+autolysosome+formation+in+cells+using+multispectral+imaging+flow+cytometry.">Quantifying autophagy: Measuring LC3 puncta and autolysosome formation in cells using multispectral imaging flow cytometry.</a> Methods. 112, 147-156 (2017).</li><li>IDEAS. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Image Data Exploration and Analysis Software User's Manual Version 6.2. , (2015).</li></ol>

我是MilliporeSigma的工​​作，MilliporeSigma是Amnis品牌ImageStream的制造商，在这项研究中使用。

执行此分析时，需要考虑几件事情。重要的是要有适当的对照样品。对于该实验，使用两种不同的对照:对照和对照+氯喹。对照样品用于设定区域的阈值。它代表自噬的基础水平，而不会阻止溶酶体降解，并且是饥饿样品的对照。然而，对照样品不是适用于与Starved + Chloroquine样品相比较的对照，因为氯喹本身会影响对照样品。因此，有必要使用Control + Chloroquine样品。 在对自噬进行任何分析之前，重要的是仅对焦点上的单个单元格（ 即，梯度RMS大于60）进行分析/门控，因为如果存在多个单元格或图像是可能会影响结果失焦了自噬体至关重要es和溶酶体正在关注适当的斑点计数和BDC3分析。在自噬分析之前必须去除凋亡细胞，因为它们可能会使结果偏斜，不应包括在内。对于所有三种标记物（ 即 LC3，p62和LAMP1）都应有适当的染色。例如，所有三个标记都是细胞内的，应该有点状信号;如果信号没有点状，或者如果它在细胞表面，则染色不合适，并且重新实验/染色。另外，对于BDC3来说，对于所有三种感兴趣的荧光标记来说，对于对于明亮的细胞是必要的。需要对积极事件进行选择，以防止BDC3对非特异性结合，成像伪像和/或噪声的测量。这是至关重要的，因为BDC3可以潜在地放大不是真实信号的伪像。由于BDC3只能在亮阳性事件上执行，因此许多单元可能不包括在最终分析中;这是espec对于没有LC3，p62和/或LAMP1的任何积累的对照细胞是真实的。因此，该测定的局限性是BDC3仅检测对于所有三种标记物呈阳性的细胞，这可能不适用于所有自噬实验。 像BDS，先前已经报告了15，16，17，20，21，22，23，24，25，26，BDC3本身并没有考虑到自噬细胞器共定位的数量，从而导致很大程度的自噬数量的变异性。因此，Rajan 等人提出的双变量方法被雇用看一下双变量图，可以问一下对于LC3，p62和LAMP1，细胞必须是阳性的;为什么有这么多的细胞有0个点？这是因为LC3信号可能足够亮以进行共定位，但它可能不符合由峰值掩模（Peak（M11，Ch11-LC3-AF647，Bright，4））设置的阈值，它被认为是点。 本文提出的方案使用MIFC来计数LC3点位点和三个自噬标记物的共定位以测量自噬通量。在基础条件（对照样本）下，自噬体数量少，"高点"发现少数细胞。随着加入抑制自噬体/溶酶体融合的氯喹，LC3斑点数量增加。由于溶酶体不能分解自噬体和位于自噬体中的p62，因此导致LC3，p62和LAMP1自体聚集体积累的共定位增加。这种作用在营养物starvat下扩增离子，诱导自噬。然而，没有添加氯喹，自噬体数量没有显着增加，这很可能是由于自噬周转率的增加。当细胞在氯喹存在下饥饿时，自噬体的共定位和数量有所增加，这支持了饥饿增加自噬通量的结论。已知EBSS是自噬的强大诱导剂。因此，预计增幅会很大。如果使用另一种方法，例如药物诱导来诱导自噬，则对照和处理的样品之间的差异可能更为微妙。 该特定方案被设计用于测量人类细胞系中的自噬，但该测定可以通过切换到该特定物种的抗体来适应其他物种。此外，分析方法可用于需要共定位的任何细胞内应用的三个探针/标记。

Macroautophagy（以下简称自噬）是一种分解代谢途径，其中损伤或功能失调的成分，长寿命蛋白质和细胞器通过溶酶体降解并被回收1 。自噬是一种动态的，多步骤的过程，涉及形成自噬体;自噬体与溶酶体的融合，形成自溶胶体;以及自溶胶体2含量的降解。用于鉴定哺乳动物系统自噬的关键生物学标记是构成自噬体膜的微管相关蛋白1A / 1B-轻链3（LC3）。在自噬过程中，胞质LC3-1与磷脂酰乙醇胺缀合形成LC3-II;然后将LC3-II并入自噬体膜3中 。自噬通量的另一个广泛使用的标记是自噬受体结合体1（SQSTM1，p62）NKS自噬货物到自噬膜4,5。 传统上用于测量自噬的方法是Western印迹和荧光显微术7 。然而，这些方法都没有被认为是"金标准"，2，6为有以两者的这些技术相关联的挑战。因为使用匀浆样品，蛋白质印迹只能给出平均值，所以观察者看不到单个细胞发生了什么。另一方面，荧光显微镜在单细胞水平上给出观察者信息，但缺乏通量能力，难以获得客观和统计学上严格的评估。近年来，通过多光谱成像流式细胞术测定LC3和p62（MIFC，见材料表 ）已经获得了广泛的应用由于其定量功率，高吞吐能力，复用电位以及对每个单元进行成像的能力，因此无法实现。其中最广泛使用的方法使用MIFC，以其伴侣分析软件一起（参见材料的表 ）来测量自噬，是通过LC3斑点或自噬体8，9，10，11，12，13，14的光点计数，15，16，17。然而，自噬体的增加并不一定意味着自噬增加，因为它也可能代表了过程2的封锁。 LC3-II周转量是通过分析细胞存在而测量自噬通量的有用参数没有溶酶体降解抑制剂，如氯喹。氯喹抑制自噬体的融合到溶酶体，由此通过阻止自噬通量溶酶体降解之前，可能会发生18允许自噬体形成，因为自噬的程度的度量的定量。另外，P62主要由自噬降解，并且如果所述自噬体和其内容的溶酶体降解被阻断，P62的累积预期17,19。 自噬是一个多步骤过程，单独测量LC3或p62不能全面了解细胞中发生的情况。最近的出版物强调，有必要检查自溶酶体2，17，20，21的同时形成。 MIFC是唯一能够通过自噬体的共定位成像到溶酶体15以测量自溶酶体的形成- 17，20，21，22，23，24，25，26。此外，还研究了使用MIFC的p62和LC3的共定位以测量自噬通量5 。在参考分析软件中，测量共定位的"特征"被称为"明细相似性R3"（BDS），并且被特别设计为比较两个图像的小而明亮的图像细节。 BDS是半径为3像素或更小的局部亮点的对数转换Pearson相关系数;换句话说，BDS计算o的程度来自两个不同荧光通道的抖动像素。亮点是相关的（ 即相同的空间位置）或不相关的（ 即，不同的空间位置）。因此，相关系数在0（不相关）和1（完全相关）之间变化。的系数是对数转化为增加的范围内的零和无穷大26，27之间。单独的BDS可能不足够; Rajan 等人发现仅使用BDS可能导致假阳性或假阴性结果21 。 BDS评估两种自噬标记的共定位，但不考虑自噬体的数量。为了说明自噬体的数量，Rajan 等包括LC3斑点21的点数计数。 Rajan 等人提出使用LC3点数与BDS的双变量散点图。使用这个双变量的情节，两个人都在e首先确定:一个细胞具有高水平的LC3斑点，一个细胞具有低水平的LC3斑点。高-LC3斑点人口进一步分为两个群体:细胞低共定位（ 即，自噬体的累积）和细胞具有高的共定位（ 即，自体溶酶体的积累）。这种双变量图可以区分具有非常少的自噬体的细胞和具有自噬体和/或自溶质体21的积累的细胞。 到目前为止，使用MIFC伴随分析软件中的单个"特征类型"（参见材料表 ），LC3，p62和LAMP1（溶酶体标记）的同时共定位是不可能的。然而，6.1版中最近推出的一个新功能叫做Bright Detail Colocalization 3（BDC3）。 BDC3比较三个图像中每个图像的明亮细节图像（在本例中为LC）3，p62和LAMP1）并量化三个探针（ 即 LC3，p62和LAMP1）的共定位。 BDC3功能计算修改后的Pearson相关系数以扩展到三个图像。由于三个图像中的亮点是相关或不相关的，相关系数在0（不相关）和1（完全相关）之间变化。系数进行对数转换，以增加0和无穷大之间的动态范围。通过使用BDC3功能切换BDS功能，Rajan 等人提出的分析方法现在可以使用三种最常用的标记来同时测量一个系统中的自噬。在单次测定中将这三种自噬标记共同定位的能力可以导致对自噬的诱导和调节的新见解。以下方案概述了诱导Jurkat细胞自噬的步骤。用LC3，p62和LAMP1抗体标记细胞;获取有关多数据的数据口腔成像流式细胞仪;并分析数据以评估自噬通量。

<table border="0" cellpadding="0" cellspacing="0" width="1012">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:308px;">15 mL centrifuge tube</td>
			<td style="width:244px;">Falcon</td>
			<td style="width:161px;">352096</td>
			<td style="width:299px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:308px;">50 mL centrifuge tube</td>
			<td>Falcon</td>
			<td>352070</td>
			<td style="width:299px;"></td>
		</tr>
		<tr height="121">
			<td height="121" style="height:121px;">AF647 labeled Donkey anti-Mouse - IgG&#160;</td>
			<td>Invitrogen</td>
			<td>A-31571</td>
			<td style="width:299px;">Donkey anti-Mouse IgG (H+L) Secondary Antibody, Alexa Fluor 647. Concntration 2mg/mL. https://www.thermofisher.com/antibody/product/Donkey-anti-Mouse-IgG-H-L-Secondary-Antibody-Polyclonal/A-31571</td>
		</tr>
		<tr height="62">
			<td height="62" style="height:62px;width:308px;">anti-human CD107a-PE (LAMP1)</td>
			<td>BioLegend</td>
			<td>328607</td>
			<td style="width:299px;">Clone H4A3. Concentration 400 &#181;g/mL. http://www.biolegend.com/pe-anti-human-cd107a-lamp-1-antibody-4967.html</td>
		</tr>
		<tr height="81">
			<td height="81" style="height:81px;">anti-human CD45- AF488</td>
			<td>BioLegend</td>
			<td>304017</td>
			<td style="width:299px;">Clone HI30. http://www.biolegend.com/alexa-fluor-488-anti-human-cd45-antibody-2738.html</td>
		</tr>
		<tr height="61">
			<td height="61" style="height:61px;">anti-human CD45- PE&#160;</td>
			<td>BioLegend</td>
			<td>304008</td>
			<td style="width:299px;">Clone HI30.&#160; http://www.biolegend.com/pe-anti-human-cd45-antibody-708.html</td>
		</tr>
		<tr height="81">
			<td height="81" style="height:81px;">anti-human CD45-AF647&#160;</td>
			<td>BioLegend</td>
			<td>304018</td>
			<td style="width:299px;">Clone HI30.&#160; http://www.biolegend.com/alexa-fluor-647-anti-human-cd45-antibody-2739.html</td>
		</tr>
		<tr height="41">
			<td height="41" style="height:41px;width:308px;">Anti-LC3 (Human) mAb clone 4E12</td>
			<td>MBL International Corporation</td>
			<td>M152-3</td>
			<td style="width:299px;">Clone 4E+12.&#160; Concentration 2 mg/mL.&#160; https://www.mblintl.com/products/m152-3</td>
		</tr>
		<tr height="81">
			<td height="81" style="height:81px;width:308px;">Anti-SQSTM1 / p62 antibody [EPR4844] - Autophagosome Marker (Alexa Fluor 488)</td>
			<td>abcam</td>
			<td>ab185015</td>
			<td style="width:299px;">Clone EPR4844.&#160; Concentration 0.5 mg/mL.&#160; http://www.abcam.com/sqstm1-p62-antibody-epr4844-autophagosome-marker-alexa-fluor-488-ab185015.html</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:308px;">Chloroquine diphosphate Salt</td>
			<td>Sigma-Aldrich</td>
			<td>C6628-25G</td>
			<td style="width:299px;"></td>
		</tr>
		<tr height="101">
			<td height="101" style="height:101px;width:308px;">Cleanser - Coulter Clenz&#160;</td>
			<td>Beckman Coulter</td>
			<td>8546931</td>
			<td style="width:299px;">Fill container with 200 mL of Cleanser.&#160; https://www.beckmancoulter.com/wsrportal/page/itemDetails?itemNumber=8546931#2/10//0/25/1/0/asc/2/8546931///0/1//0/</td>
		</tr>
		<tr height="61">
			<td height="61" style="height:61px;width:308px;">DAPI Stain 5mg/mL</td>
			<td>MilliporeSigma</td>
			<td>508741</td>
			<td style="width:299px;">http://www.emdmillipore.com/US/en/product/DAPI-Stain---CAS-28718-90-3---Calbiochem,EMD_BIO-508741</td>
		</tr>
		<tr height="121">
			<td height="121" style="height:121px;width:308px;">Debubbler - 70% Isopropanol</td>
			<td>MilliporeSigma</td>
			<td>1.3704</td>
			<td style="width:299px;">Fill container with 200 mL of Debubbler.&#160; http://www.emdmillipore.com/US/en/product/2-Propanol-70%25-%28V%2FV%29-0.1-%C2%B5m-filtred,MDA_CHEM-137040?ReferrerURL=https%3A%2F%2Fwww.google.com%2F</td>
		</tr>
		<tr height="41">
			<td height="41" style="height:41px;width:308px;">Dulbecco&#39;s Phosphate Buffered Saline 10X</td>
			<td>MilliporeSigma</td>
			<td>BSS-2010-B</td>
			<td style="width:299px;">&#160;Ca++Mg++ Free&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:308px;">Dulbecco&#39;s Phosphate Buffered Saline 1X</td>
			<td>MilliporeSigma</td>
			<td>BSS-1006-B</td>
			<td style="width:299px;">PBS Ca++Mg++ Free&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:308px;">Earle&#39;s Balanced Salt Solution 1X</td>
			<td>Gibco</td>
			<td>14155</td>
			<td style="width:299px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:308px;">Fetal Bovine Serum</td>
			<td>HyClone</td>
			<td>SH30071.03</td>
			<td style="width:299px;"></td>
		</tr>
		<tr height="241">
			<td height="241" style="height:241px;width:308px;">Formaldehyde, 10%, methanol free, Ultra Pure</td>
			<td>Polysciences, Inc.</td>
			<td>04018</td>
			<td style="width:299px;">This is what is used for the 4% and 1% Formalin. CAUTION: Formalin/Formaldehyde toxic by inhalation and if swallowed.&#160; Irritating to the eyes, respiratory systems and skin.&#160; May cause sensitization by inhalation or skin contact. Risk of serious damage to eyes.&#160; Potential cancer hazard.&#160; http://www.polysciences.com/default/catalog-products/life-sciences/histology-microscopy/fixatives/formaldehydes/formaldehyde-10-methanol-free-pure/</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:308px;">Hanks&#39; Balanced Salt Solution 1X</td>
			<td>Gibco</td>
			<td>14175</td>
			<td style="width:299px;"></td>
		</tr>
		<tr height="41">
			<td height="41" style="height:41px;width:308px;">Jurkat, Clone E6-1 (ATCC TIB-152)</td>
			<td>ATCC</td>
			<td>TIB-152</td>
			<td style="width:299px;">https://www.atcc.org/products/all/TIB-152.aspx</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:308px;">MEM Non-Essential Amino Acids 100X</td>
			<td>HyClone</td>
			<td>SH30238.01</td>
			<td style="width:299px;"></td>
		</tr>
		<tr height="201">
			<td height="201" style="height:201px;width:308px;">MIFC - ImageStreamX Mark II</td>
			<td>MilliporeSigma</td>
			<td>100220</td>
			<td style="width:299px;">A 2 camera ImageStreamX Mark II eqiped with the 405nm, 488nm, and 642nm lasers was used. http://www.emdmillipore.com/US/en/life-science-research/cell-analysis/amnis-imaging-flow-cytometers/imagestreamx-Mark-ii-imaging-flow-cytometer/VaSb.qB.QokAAAFLzRop.zHe,nav?cid=BI-XX-BDS-P-GOOG-FLOW-B325-0006</td>
		</tr>
		<tr height="61">
			<td height="61" style="height:61px;width:308px;">MIFC analysis software - IDEAS 6.2</td>
			<td>MilliporeSigma</td>
			<td>100220</td>
			<td style="width:299px;">The companion software to the MIFC (ImageStreamX MKII).&#160; IDEAS version 6.2</td>
		</tr>
		<tr height="61">
			<td height="61" style="height:61px;width:308px;">MIFC software - INSPIRE</td>
			<td>MilliporeSigma</td>
			<td>100220</td>
			<td style="width:299px;">This is the software that runs the MIFC (ImageStreamX MKII). INSPIRE version 200.1.388.0</td>
		</tr>
		<tr height="41">
			<td height="41" style="height:41px;width:308px;">PE anti-human CD107a (LAMP-1) Antibody clone H4A3</td>
			<td>BioLegend</td>
			<td>328608</td>
			<td style="width:299px;">http://www.biolegend.com/pe-anti-human-cd107a-lamp-1-antibody-4967.html</td>
		</tr>
		<tr height="41">
			<td height="41" style="height:41px;width:308px;">Penicllin/Streptomycin/Glutamine solution 100X</td>
			<td>HyClone</td>
			<td>SV30082.1</td>
			<td style="width:299px;"></td>
		</tr>
		<tr height="61">
			<td height="61" style="height:61px;width:308px;">Rinse - Ultrapure water or deionized water</td>
			<td>NA</td>
			<td>NA</td>
			<td style="width:299px;">You can use any ultrapure water or deionized water.&#160; Fill container with 900 mL of Rinse.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:308px;">RPMI-1640 Medium 1X</td>
			<td>HyClone</td>
			<td>SH30027.01</td>
			<td style="width:299px;"></td>
		</tr>
		<tr height="81">
			<td height="81" style="height:81px;width:308px;">Sheath - PBS</td>
			<td>MilliporeSigma</td>
			<td>BSS-1006-B</td>
			<td style="width:299px;">This is the same as Dulbecco&#39;s Phosphate Buffered Saline 1X&#160; Ca++MG++ free.&#160; Fill container with 900mL of Sheath.</td>
		</tr>
		<tr height="101">
			<td height="101" style="height:101px;width:308px;">Siliconized polypropylene microcentrifuge tubes</td>
			<td>Fisherbrand</td>
			<td>02-681-320</td>
			<td style="width:299px;">Fisherbran Siliconized Low-Retention Microcentrifuge Tubes 1.5 mL. https://www.fishersci.com/shop/products/fisherbrand-siliconized-low-retention-microcentrifuge-tubes-8/p-193936</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:308px;">Sodium Pyruvate solution (100mM)</td>
			<td>HyClone</td>
			<td>SH30239.01</td>
			<td style="width:299px;"></td>
		</tr>
		<tr height="81">
			<td height="81" style="height:81px;width:308px;">Sterilizer - 0.4-0.7% Hypochlorite</td>
			<td>VWR</td>
			<td>JT9416-1</td>
			<td style="width:299px;">This is assentually 10% Clorox bleach that can be made by deluting Clorox bleach with water.&#160; Fill container with 200 mL of Sterilzer.</td>
		</tr>
		<tr height="121">
			<td height="121" style="height:121px;width:308px;">System Calibration Reagent - SpeedBead</td>
			<td>MilliporeSigma</td>
			<td>400041</td>
			<td style="width:299px;">Each tube holds ~10 mL.&#160; https://www.emdmillipore.com/US/en/life-science-research/cell-analysis/amnis-imaging-flow-cytometers/support-training/XDqb.qB.wQMAAAFLBDUp.zHu,nav&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:308px;">T75 flask</td>
			<td>Falcon</td>
			<td>353136</td>
			<td style="width:299px;"></td>
		</tr>
		<tr height="101">
			<td height="101" style="height:101px;width:308px;">TRITON X-100, PROTEIN GRADE Detergent, 10% Solution, Sterile-Filtered</td>
			<td>MilliporeSigma</td>
			<td>648463-50ML</td>
			<td style="width:299px;">http://www.emdmillipore.com/US/en/product/TRITON-X-100,-PROTEIN-GRADE-Detergent,-10%25-Solution,-Sterile-Filtered---CAS-9002-93-1---Calbiochem,EMD_BIO-648463</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:308px;">Water, Cell Culture Grade&#160;</td>
			<td>HyClone</td>
			<td>SH30529.03</td>
			<td style="width:299px;"></td>
		</tr>
	</tbody>
</table>

assessing autophagic flux by measuring lc3, p62, and lamp1 co-localization using multispectral imaging flow cytometry

自噬是分解代谢途径，其中在生长和分化期间积累的正常或功能失调的细胞组分通过溶酶体降解并被再循环。在自噬过程中，细胞质LC3蛋白被脂质化并引入自噬体膜。然后自噬体与溶酶体融合以形成自体溶质，其中发生自噬体囊泡及其内含物的分解。与LC3结合的泛素相关蛋白p62也用于监测自噬通量。进行自噬的细胞应该证明p62，LC3和溶酶体标记物的共定位。已经使用免疫荧光显微镜来以每细胞为基础目视鉴定LC3斑点，p62和/或溶酶体。然而，客观和统计上严格的评估可能难以获得。为了克服这些问题，使用多光谱成像流式细胞术以及比较光亮度的分析特征来自三个自噬标记（LC3，p62和溶酶体LAMP1）的尾部图像，并量化它们的共定位，结合LC3点计数，以客观，定量和统计学鲁棒的方式测量自噬。

该分析方法使用多个特征来评估自噬通量。为了充分了解最终的双变量图，必须首先对个别分析特征进行调查。自噬的计数是衡量自噬的一种合乎逻辑的方法;然而，LC3斑点的大小/形状/亮度可以在细胞之间显着变化。变异可能使得在分析软件中手动计数自噬体或使用点数特征难以计数。因此，由于自噬体的大变异性，无斑点特征将是完美的。然而，大多数单元格26都能实现良好的点数功能。 图3示出了使用不同的斑点掩模的Jurkat细胞中LC3斑点的斑点掩蔽的实例。为此数据集选择的点计数功能是Spot Count_Peak（M11，Ch11-LC3-AF647，Bright，4）_4，这意味着点计数功能计数为pe在通道11（Ch11-LC3-AF647）上的默认通道11掩码（M11）中标识的ak掩码，点到单元背景比为4（Bright，4）。 图4显示了用反LC3-AF647标记的对照，对照+氯喹，饥饿和饥饿+氯喹Jurkat细胞的斑点计数直方图和代表性图像。控制和饥饿平均斑点数没有显着差异;与氯喹相比，对照+氯喹与饥饿+氯喹相比，平均值差异很大。 下一个调查功能是BDC3。 BDC3是三种标记物/探针的共定位的测量，在这种情况下，LC3，p62和LAMP1。 图5A - 5D显示了用抗p62-AF488标记的对照，对照+氯喹，饥饿和饥饿+氯喹Jurkat细胞的BDC3直方图，抗LAMP1-PE和抗LC3-AF647。控制平均值与饥饿平均值之间存在转移，以及对照+氯喹平均值与饥饿+氯喹平均值之间的偏差。然而，从图5E - 5H中的平均BDC3评分中观察细胞的图像，样本之间的差异比直方图可能导致人们相信更大。这是因为BDC3不考虑自噬细胞器的数量，导致相同BDC3评分的自噬体数量的变化程度很大。在大多数情况下，所有三个探针之间存在重叠，因为即使在基础水平，p62，LAMP1和LC3应在一定程度上共同定位或驻留在细胞中的相似区域。相比之下，不能共定位的三个探针的实例是用于Starved + Chloroquine样品的抗p62-AF488，抗LC3-AF647和DAPI核染料， 如图6所示。/ P&gt; 当点计数特征和BDC3特征相结合时，存在提高区别各种样本/条件的能力的不同亚群的存在是明显的。 图7显示了四个样品的LC3与BDC3 p62 / LAMP1 / LC3的斑点数的双变量图:对照，对照+氯喹，饥饿和饥饿+氯喹。对照样品用于设置三个群体的门控策略:低斑点，高斑点/低BDC3和高斑点/高BDC3。对照样品显示大于98％的细胞具有1个或更少的斑点。高点/低BDC3和高点/高BDC3之间的边界被设置为BDC3得分为1，因为对照样本的91％以上的BDC3得分小于1.双变量图的结果总结如表1所示。 年龄= "1"&gt; <img alt="图1" class="xfigimg" src="/files/ftp_upload/55637/55637fig1.jpg" /> 图1:MIFC仪器设置。本实验步骤8中概述的MIFC仪器设置的屏幕截图。 <a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/55637/55637fig1large.jpg" target="_blank">请点击此处查看此图的较大版本。</a> <img alt="图2" class="xfigimg" src="/files/ftp_upload/55637/55637fig2.jpg" /> 图2:分析软件门控策略。分析软件选通方案的屏幕截图，在协议的步骤9中概述。 <a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/55637/55637fig2large.jpg" target="_blank">请点击此处查看此图的较大版本。</a> fig3.jpg"/&gt; 图3:LC3斑点掩蔽。 Jurkat细胞图像和掩模用于创建点计数功能。显示为BrightField（BF），LC3-AF647，Peak（M11，Ch11-LC3-AF647，Bright，2），Peak（M11，Ch11-LC3-AF647，Bright，4），Peak（M11，Ch11-LC3-AF647 ，Bright，5），Spot（M11，Ch11-LC3-AF647，Bright，5,3,1）和Spot（M11，Ch11-LC3-AF647，Bright，6,2,1）。最适合所有细胞的面膜为Peak（M11，Ch11-LC3-AF647，Bright，4）。 <a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/55637/55637fig3large.jpg" target="_blank">请点击此处查看此图的较大版本。</a> <img alt="图4" class="xfigimg" src="/files/ftp_upload/55637/55637fig4.jpg" /> 图4:LC3点数直方图。使用点计数功能Spot Count_Peak（M11，Ch11-LC3-AF647，Bright，4）_4和Control（ A ，浅蓝色），Control + Chloroquin的LC3-AF647点计数直方图e（ B ，蓝色），饥饿（ C ，粉红色）和饥饿+氯喹（ D ，红色）。对照，对照+氯喹，饥饿和饥饿+氯喹的平均斑数分别为0.07,1.13,10.10和2.77。 BF，LC3-AF647（红色），DAPI核染料（蓝色）和代表性细胞的LC3-AF647和DAPI图像的平均斑点数的复合物显示为对照（ E ，0个斑点），对照+氯喹F ，1点），饥饿（ G ，0个点）和饥饿+氯喹（ H ，3个点）。 <a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/55637/55637fig4large.jpg" target="_blank">请点击此处查看此图的较大版本。</a> <img alt="图5" class="xfigimg" src="/files/ftp_upload/55637/55637fig5.jpg" /> 图5:p62 / LAMP1 / LC3的BDC3直方图。 BDC3 p62 / LAMP1 / LC3直方图对照（ A ，淡蓝色），对照+氯喹（ B ，蓝色），饥饿（ C ，粉红色）和饥饿+氯喹（ D ，红色）。对照，对照+氯喹，饥饿和饥饿+氯喹的平均BDC3评分分别为0.57,0.82,0.74和0.98。 BF; p62-AF488（绿色）; LAMP1-PE（黄色）; LC3-AF647（红色）;对照（ E ），对照+氯喹（ F ），饥饿（ G ），饥饿+氯喹（ F ），饥饿+氯喹H ）。 <a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/55637/55637fig5large.jpg" target="_blank">请点击此处查看此图的较大版本。</a> <img alt="图6" class="xfigimg" src="/files/ftp_upload/55637/55637fig6.jpg" /> 图6:p62 / L的BDC3直方图C3 / DAPI为饥饿+氯喹样品。 （ A ）显示了Starved + Chloroquine样品的BDC3 p62 / LC3 / DAPI直方图。平均BDC3评分为0.07。 （ B ）BF; p62-AF488（绿色）; LC3-AF647（红色）; DAPI（蓝色）;对于Starved + Chloroquine样品，显示了平均BDC3的代表性细胞的p62-AF488，LC3-AF647和DAPI图像的复合物。 <a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/55637/55637fig6large.jpg" target="_blank">请点击此处查看此图的较大版本。</a> <img alt="图7" class="xfigimg" src="/files/ftp_upload/55637/55637fig7.jpg" /> 图7:LC3点数与BDC3 p62 / LAMP1 / LC3的双变量图。 （ A ）对照，对照+氯喹，饥饿和饥饿+氯喹Jurkat细胞的LC3斑点数与BDC3 p62 / LAMP1 / LC3的双变量图。 （ B ）BF; p62-AF488（绿色）; LAMP1-PE（黄色）; LC3-AF647（红色）;对于Starved + Chloroquine样品，显示了来自三个区域（ 即，低斑点，高斑点/低BDC3和高斑点/高BDC3）的p62-AF488，LAMP1-PE和LC3-AF647图像的复合物。 <a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/55637/55637fig7large.jpg" target="_blank">请点击此处查看此图的较大版本。</a> <table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always"><tbody><tr><td></td><td>细胞计数</td><td>亮度细节共定位3平均值</td><td>点数LC3平均值</td><td> ％低点</td><td> ％高点/低BDC3 </td><td> ％高点/高BDC3 </td></tr><tr><td>控制</td><td> 439 </td><td> 0.57 </td><td> 0.07 </td><td> 98.2 </td><td> 1.8 </td><td> 0.0 </td></tr><tr><td>对照+氯喹</td><td> 1432 </td><td> 0.82 </td><td> 1.13 </td><td> 68.9 </TD&gt; <td> 19.5 </td><td> 11.7 </td></tr><tr><td>饥饿</td><td> 1204 </td><td> 0.74 </td><td> 0.10 </td><td> 98.4 </td><td> 0.6 </td><td> 1.0 </td></tr><tr><td>饥饿+氯喹</td><td> 1811 </td><td> 0.98 </td><td> 2.77 </td><td> 32.1 </td><td> 36.9 </td><td> 31.0 </td></tr></tbody></table> 表1:Jurkat LC3点数与 BDC3 p62 / LAMP1 / LC3双变量图的总结

Watch this Scientific Journal Video about Assessing Autophagic Flux by Measuring LC3, p62, and LAMP1 Co-localization Using Multispectral Imaging Flow Cytometry at JoVE.com

Assessing Autophagic Flux by Measuring LC3, p62, and LAMP1 Co-localization Using Multispectral Imaging Flow Cytometry

在这里，具有分析特征的多光谱成像流式细胞术可以比较3个自噬标记的明亮细节图像，并量化其共定位以及LC3斑点计数，用于以客观，定量和统计学鲁棒的方式测量自噬。

通过使用多光谱成像流式细胞术测量LC3，p62和LAMP1共定位评估自噬通量

Autophagy is a catabolic pathway in which normal or dysfunctional cellular components that accumulate during growth and differentiation are degraded via ...

assessing-autophagic-flux-measuring-lc3-p62-lamp1-co-localization

Nanyang Technological University

Research

JoVE Journal

Biology

31.0K 次观看.  MilliporeSigma. 在这里，具有分析特征的多光谱成像流式细胞术可以比较3个自噬标记的明亮细节图像，并量化其共定位以及LC3斑点计数，用于以客观，定量和统计学鲁棒的方式测量自噬。 

视频: Assessing Autophagic Flux by Measuring LC3, p62, and LAMP1 Co-localization Using Multispectral Imaging Flow Cytometry

IP-FCM:  Immunoprecipitation Detected by Flow Cytometry

Immunoprecipitation detected by flow cytometry (IP-FCM) is an efficient method for detecting and quantifying protein-protein interactions. The basic principle extends that of sandwich ELISA, wherein the captured primary analyte can be detected together with other molecules physically associated within multiprotein complexes. The procedure involves covalent coupling of polystyrene latex microbeads with immunoprecipitating monoclonal antibodies (mAb) specific for a protein of interest, incubating these beads with cell lysates, probing captured protein complexes with fluorochrome-conjugated probes, and analyzing bead-associated fluorescence by flow cytometry. IP-FCM is extremely sensitive, allows analysis of proteins in their native (non-denatured) state, and is amenable to either semi-quantitative or quantitative analysis. As additional advantages, IP-FCM requires no genetic engineering or specialized equipment, other than a flow cytometer, and it can be readily adapted for high-throughput applications.

The IP-FCM method is presented, which allows a sensitive, robust, biochemical assessment of native protein-protein interactions, without requiring genetic engineering or large sample sizes.

IP - FCM:免疫沉淀，流式细胞仪检测

Immunoprecipitation detected by flow cytometry (IP-FCM) is an efficient method for detecting and quantifying protein-protein interactions. The basic ...

科研

生物学

Flow Cytometry Purification of Mouse Meiotic Cells

The heterogeneous nature of cell types in the testis and the absence of meiotic cell culture models have been significant hurdles to the study of the unique differentiation programs that are manifest during meiosis. Two principal methods have been developed to purify, to varying degrees, various meiotic fractions from both adult and immature animals: elutriation or Staput (sedimentation) using BSA and/or percoll gradients. Both of these methods rely on cell size and density to separate meiotic cells1-5. Overall, except for few cell populations6, these protocols fail to yield sufficient purity of the numerous meiotic cell populations that are necessary for detailed molecular analyses. Moreover, with such methods usually one type of meiotic cells can be purified at a given time, which adds an extra level of complexity regarding the reproducibility and homogeneity when comparing meiotic cell samples.
Here, we describe a refined method that allows one to easily visualize, identify, and purify meiotic cells, from germ cells to round spermatids, using FACS combined with Hoechst 33342 staining7,8. This method provides an overall snapshot of the entire meiotic process and allows one to highly purify viable cells from most stage of meiosis. These purified cells can then be analyzed in detail for molecular changes that accompany progression through meiosis, for example changes in gene expression9,10and the dynamics of nucleosome occupancy at hotspots of meiotic recombination11.

An efficient method to obtain highly purified viable meiotic fractions from mouse testis is described, which combines a refined cell dissociation protocol with fluorescent activated cell sorting (FACS). This method takes advantage of differences in the DNA content and nuclear density of discrete meiotic fractions.

流动小鼠减数分裂细胞的流式细胞仪净化

The heterogeneous nature of cell types in the testis and the absence of meiotic cell culture models have been significant hurdles to the study of the ...

Measuring Cell Cycle Progression Kinetics with Metabolic Labeling and Flow Cytometry

Precise control of the initiation and subsequent progression through the various phases of the cell cycle are of paramount importance in proliferating cells. Cell cycle division is an integral part of growth and reproduction and deregulation of key cell cycle components have been implicated in the precipitating events of carcinogenesis 1,2. Molecular agents in anti-cancer therapies frequently target biological pathways responsible for the regulation and coordination of cell cycle division 3. Although cell cycle kinetics tend to vary according to cell type, the distribution of cells amongst the four stages of the cell cycle is rather consistent within a particular cell line due to the consistent pattern of mitogen and growth factor expression. Genotoxic events and other cellular stressors can result in a temporary block of cell cycle progression, resulting in arrest or a temporary pause in a particular cell cycle phase to allow for instigation of the appropriate response mechanism. 
The ability to experimentally observe the behavior of a cell population with reference to their cell cycle progression stage is an important advance in cell biology. Common procedures such as mitotic shake off, differential centrifugation or flow cytometry-based sorting are used to isolate cells at specific stages of the cell cycle 4-6. These fractionated, cell cycle phase-enriched populations are then subjected to experimental treatments. Yield, purity and viability of the separated fractions can often be compromised using these physical separation methods. As well, the time lapse between separation of the cell populations and the start of experimental treatment, whereby the fractionated cells can progress from the selected cell cycle stage, can pose significant challenges in the successful implementation and interpretation of these experiments.
Other approaches to study cell cycle stages include the use of chemicals to synchronize cells. Treatment of cells with chemical inhibitors of key metabolic processes for each cell cycle stage are useful in blocking the progression of the cell cycle to the next stage. For example, the ribonucleotide reductase inhibitor hydroxyurea halts cells at the G1/S juncture by limiting the supply of deoxynucleotides, the building blocks of DNA. Other notable chemicals include treatment with aphidicolin, a polymerase alpha inhibitor for G1 arrest, treatment with colchicine and nocodazole, both of which interfere with mitotic spindle formation to halt cells in M phase and finally, treatment with the DNA chain terminator 5-fluorodeoxyridine to initiate S phase arrest 7-9. Treatment with these chemicals is an effective means of synchronizing an entire population of cells at a particular phase. With removal of the chemical, cells rejoin the cell cycle in unison. Treatment of the test agent following release from the cell cycle blocking chemical ensures that the drug response elicited is from a uniform, cell cycle stage-specific population. However, since many of the chemical synchronizers are known genotoxic compounds, teasing apart the participation of various response pathways (to the synchronizers vs. the test agents) is challenging. 
Here we describe a metabolic labeling method for following a subpopulation of actively cycling cells through their progression from the DNA replication phase, through to the division and separation of their daughter cells. Coupled with flow cytometry quantification, this protocol enables for measurement of kinetic progression of the cell cycle in the absence of either mechanically- or chemically- induced cellular stresses commonly associated with other cell cycle synchronization methodologies 10. In the following sections we will discuss the methodology, as well as some of its applications in biomedical research.

Tracking subtle changes in the progression and kinetics of cell cycle stages can be accomplished by use of a combination of metabolic labeling of nucleic acids with BrdU and total genomic DNA staining via Propidium Iodide. This method avoids the need of chemical synchronization of cycling cells, thereby preventing the introduction of non-specific DNA damage, which in turn affects cell cycle progression.

代谢标记和流式细胞仪测定细胞周期进程的动力学

Precise control of the initiation and subsequent progression through the various phases of the cell cycle are of paramount importance in proliferating ...

Optimized Staining and Proliferation Modeling Methods for Cell Division Monitoring using Cell Tracking Dyes

Fluorescent cell tracking dyes, in combination with flow and image cytometry, are powerful tools with which to study the interactions and fates of different cell types in vitro and in vivo.1-5 Although there are literally thousands of publications using such dyes, some of the most commonly encountered cell tracking applications include monitoring of:
<ol>
	<li>stem and progenitor cell quiescence, proliferation and/or differentiation6-8</li>
	<li>antigen-driven membrane transfer9 and/or precursor cell proliferation3,4,10-18 and</li>
	<li>immune regulatory and effector cell function1,18-21.</li>
</ol>
Commercially available cell tracking dyes vary widely in their chemistries and fluorescence properties but the great majority fall into one of two classes based on their mechanism of cell labeling. "Membrane dyes", typified by PKH26, are highly lipophilic dyes that partition stably but non-covalently into cell membranes1,2,11. "Protein dyes", typified by CFSE, are amino-reactive dyes that form stable covalent bonds with cell proteins4,16,18. Each class has its own advantages and limitations. The key to their successful use, particularly in multicolor studies where multiple dyes are used to track different cell types, is therefore to understand the critical issues enabling optimal use of each class2-4,16,18,24.
The protocols included here highlight three common causes of poor or variable results when using cell-tracking dyes. These are:
<ol>
	<li>Failure to achieve bright, uniform, reproducible labeling. This is a necessary starting point for any cell tracking study but requires attention to different variables when using membrane dyes than when using protein dyes or equilibrium binding reagents such as antibodies.</li>
	<li>Suboptimal fluorochrome combinations and/or failure to include critical compensation controls. Tracking dye fluorescence is typically 102 - 103 times brighter than antibody fluorescence. It is therefore essential to verify that the presence of tracking dye does not compromise the ability to detect other probes being used.</li>
	<li>Failure to obtain a good fit with peak modeling software. Such software allows quantitative comparison of proliferative responses across different populations or stimuli based on precursor frequency or other metrics. Obtaining a good fit, however, requires exclusion of dead/dying cells that can distort dye dilution profiles and matching of the assumptions underlying the model with characteristics of the observed dye dilution profile.</li>
</ol>
Examples given here illustrate how these variables can affect results when using membrane and/or protein dyes to monitor cell proliferation.

Successful use of cell tracking dyes to monitor immune cell function and proliferation involves several critical steps. We describe methods for: 1) obtaining bright, uniform, reproducible label-ing with membrane dyes; 2) selecting fluorochromes and data acquisition conditions; and 3) choosing a model to quantify cell proliferation based on dye dilution.

优化细胞分裂监测细胞示踪染料的染色和扩散建模方法

Fluorescent cell tracking dyes, in combination with flow and image cytometry, are powerful tools with which to study the interactions and fates of ...

Measuring Intracellular Ca2+ Changes in Human Sperm using Four Techniques: Conventional Fluorometry, Stopped Flow Fluorometry, Flow Cytometry and Single Cell Imaging

Spermatozoa are male reproductive cells especially designed to reach, recognize and fuse with the egg. To perform these tasks, sperm cells must be prepared to face a constantly changing environment and to overcome several physical barriers. Being in essence transcriptionally and translationally silent, these motile cells rely profoundly on diverse signaling mechanisms to orient themselves and swim in a directed fashion, and to contend with challenging environmental conditions during their journey to find the egg. In particular, Ca2+-mediated signaling is pivotal for several sperm functions: activation of motility, capacitation (a complex process that prepares sperm for the acrosome reaction) and the acrosome reaction (an exocytotic event that allows sperm-egg fusion). The use of fluorescent dyes to track intracellular fluctuations of this ion is of remarkable importance due to their ease of application, sensitivity, and versatility of detection. Using one single dye-loading protocol we utilize four different fluorometric techniques to monitor sperm Ca2+ dynamics. Each technique provides distinct information that enables spatial and/or temporal resolution, generating data both at single cell and cell population levels.

Measuring Intracellular Ca2+ Changes in Human Sperm using Four Techniques: Conventional Fluorometry, Stopped Flow Fluorometry, Flow Cytometry and Single Cell Imaging

Intracellular Ca2+ dynamics are very important in sperm physiology and Ca2+-sensitive fluorescent dyes constitute a versatile tool to study them. Population experiments (fluorometry and stopped flow fluorometry) and single cell experiments (flow cytometry and single cell imaging) are used to track spatio-temporal [Ca2+] changes in human sperm cells.

测量细胞内Ca<sup&gt; +</sup在人类精子的变化采用4项技术:传统的荧光，停流荧光，流式细胞术及单细胞成像

Spermatozoa  are male reproductive cells especially designed to reach, recognize and fuse  with the egg. To perform these tasks, sperm cells must be ...

Identification of a Murine Erythroblast Subpopulation  Enriched in Enucleating Events by Multi-spectral Imaging Flow Cytometry

Erythropoiesis in mammals concludes with the dramatic process of enucleation that results in reticulocyte formation. The mechanism of enucleation has not yet been fully elucidated. A common problem encountered when studying the localization of key proteins and structures within enucleating erythroblasts by microscopy is the difficulty to observe a sufficient number of cells undergoing enucleation.&#160;We have developed a novel analysis protocol using multiparameter high-speed cell imaging in flow (Multi-Spectral Imaging Flow Cytometry), a method that combines immunofluorescent microscopy with flow cytometry, in order to identify efficiently a significant number of enucleating events, that allows to obtain measurements and perform statistical analysis.
We first describe here two in vitro erythropoiesis culture methods used in order to synchronize murine erythroblasts and increase the probability of capturing enucleation at the time of evaluation.&#160;Then, we describe in detail the staining of erythroblasts after fixation and permeabilization in order to study the localization of intracellular proteins or lipid rafts during enucleation by multi-spectral imaging flow cytometry.&#160;Along with size and DNA/Ter119 staining which are used to identify the orthochromatic erythroblasts, we utilize the parameters &#8220;aspect ratio&#8221; of a cell in the bright-field channel that aids in the recognition of elongated cells and &#8220;delta centroid XY Ter119/Draq5&#8221; that allows the identification of cellular events in which the center of Ter119 staining (nascent reticulocyte) is far apart from the center of Draq5 staining (nucleus undergoing extrusion), thus indicating a cell about to enucleate.&#160;The subset of the orthochromatic erythroblast population with high delta centroid and low aspect ratio is highly enriched in enucleating cells.

The present protocol describes a novel method of identifying a population of enucleating orthochromatic erythroblasts by multi-spectral imaging flow cytometry, providing a visualization of the erythroblast enucleation process.

一个小鼠红细胞亚群富集去核活动由多光谱成像流式细胞仪鉴定

Erythropoiesis in mammals concludes with the dramatic process of enucleation that results in reticulocyte formation. The mechanism of enucleation has not ...

In Vivo 4-Dimensional Tracking of Hematopoietic Stem and Progenitor Cells in Adult Mouse Calvarial Bone Marrow

Through a delicate balance between quiescence and proliferation, self renewal and production of differentiated progeny, hematopoietic stem cells (HSCs) maintain the turnover of all mature blood cell lineages. The coordination of the complex signals leading to specific HSC fates relies upon the interaction between HSCs and the intricate bone marrow microenvironment, which is still poorly understood[1-2].
We describe how by combining a newly developed specimen holder for stable animal positioning with multi-step confocal and two-photon in vivo imaging techniques, it is possible to obtain high-resolution 3D stacks containing HSPCs and their surrounding niches and to monitor them over time through multi-point time-lapse imaging. High definition imaging allows detecting ex vivo labeled hematopoietic stem and progenitor cells (HSPCs) residing within the bone marrow. Moreover, multi-point time-lapse 3D imaging, obtained with faster acquisition settings, provides accurate information about HSPC movement and the reciprocal interactions between HSPCs and stroma cells.
Tracking of HSPCs in relation to GFP positive osteoblastic cells is shown as an exemplary application of this method. This technique can be utilized to track any appropriately labeled hematopoietic or stromal cell of interest within the mouse calvarium bone marrow space.

In Vivo 4-Dimensional Tracking of Hematopoietic Stem and Progenitor Cells in Adult Mouse Calvarial Bone Marrow

The nature of the interactions between hematopoietic stem and progenitor cells (HSPCs) and bone marrow niches is poorly understood. Custom hardware modifications and a multi-step acquisition protocol allow the use of two-photon and confocal microscopy to image ex vivo labeled HSPCs homed within bone marrow areas, tracking interactions and movement.

在造血干细胞和祖细胞的成年小鼠颅骨骨髓体内四维跟踪

Through a delicate balance between quiescence and proliferation, self renewal and production of differentiated progeny, hematopoietic stem cells (HSCs) ...

Cytosolic Calcium Measurements in Renal Epithelial Cells by Flow Cytometry

A variety of cellular processes, both physiological and pathophysiological, require or are governed by calcium, including exocytosis, mitochondrial function, cell death, cell metabolism and cell migration to name but a few. Cytosolic calcium is normally maintained at low nanomolar concentrations; rather it is found in high micromolar to millimolar concentrations in the endoplasmic reticulum, mitochondrial matrix and the extracellular compartment. Upon stimulation, a transient increase in cytosolic calcium serves to signal downstream events. Detecting changes in cytosolic calcium is normally performed using a live cell imaging set up with calcium binding dyes that exhibit either an increase in fluorescence intensity or a shift in the emission wavelength upon calcium binding. However, a live cell imaging set up is not freely accessible to all researchers. Alternative detection methods have been optimized for immunological cells with flow cytometry and for non-immunological adherent cells with a fluorescence microplate reader. Here, we describe an optimized, simple method for detecting changes in epithelial cells with flow cytometry using a single wavelength calcium binding dye. Adherent renal proximal tubule epithelial cells, which are normally difficult to load with dyes, were loaded with a fluorescent cell permeable calcium binding dye in the presence of probenecid, brought into suspension and calcium signals were monitored before and after addition of thapsigargin, tunicamycin and ionomycin.

Calcium is involved in numerous physiological and pathophysiological signaling pathways. Live cell imaging requires specialized equipment and can be time consuming. A quick, simple method using a flow cytometer to determine relative changes in cytosolic calcium in adherent epithelial cells brought into suspension was optimized.

在肾小管上皮细胞胞浆钙的测量流式细胞仪

A variety of cellular processes, both physiological and pathophysiological, require or are governed by calcium, including exocytosis, mitochondrial ...

Quantitation of Protein Expression and Co-localization Using Multiplexed Immuno-histochemical Staining and Multispectral Imaging

Immunohistochemistry is a commonly used clinical and research lab detection technique for investigating protein expression and localization within tissues. Many semi-quantitative systems have been developed for scoring expression using immunohistochemistry, but inherent subjectivity limits reproducibility and accuracy of results. Furthermore, the investigation of spatially overlapping biomarkers such as nuclear transcription factors is difficult with current immunohistochemistry techniques. We have developed and optimized a system for simultaneous investigation of multiple proteins using high throughput methods of multiplexed immunohistochemistry and multispectral imaging. Multiplexed immunohistochemistry is performed by sequential application of primary antibodies with secondary antibodies conjugated to horseradish peroxidase or alkaline phosphatase. Different chromogens are used to detect each protein of interest. Stained slides are loaded into an automated slide scanner and a protocol is created for automated image acquisition. A spectral library is created by staining a set of slides with a single chromogen on each. A subset of representative stained images are imported into multispectral imaging software and an algorithm for distinguishing tissue type is created by defining tissue compartments on images. Subcellular compartments are segmented by using hematoxylin counterstain and adjusting the intrinsic algorithm. Thresholding is applied to determine positivity and protein co-localization. The final algorithm is then applied to the entire set of tissues. Resulting data allows the user to evaluate protein expression based on tissue type (ex. epithelia vs. stroma) and subcellular compartment (nucleus vs. cytoplasm vs. plasma membrane). Co-localization analysis allows for investigation of double-positive, double-negative, and single-positive cell types. Combining multispectral imaging with multiplexed immunohistochemistry and automated image acquisition is an objective, high-throughput method for investigation of biomarkers within tissues.

Immunohistochemistry is a powerful lab technique for evaluating protein localization and expression within tissues. Current semi-automated methods for quantitation introduce subjectivity and often create irreproducible results. Herein, we describe methods for multiplexed immunohistochemistry and objective quantitation of protein expression and co-localization using multispectral imaging.

蛋白表达和共定位使用复用免疫组织化学染色和多光谱成像定量

Immunohistochemistry is a commonly used clinical and research lab detection technique for investigating protein expression and localization within ...

Measuring Endoreduplication by Flow Cytometry of Isolated Tuber Protoplasts

Endoreduplication, the replication of a cell's nuclear genome without subsequent cytokinesis, yields cells with increased DNA content and is associated with specialization, development and increase in cellular size. In plants, endoreduplication seems to facilitate the growth and expansion of certain tissues and organs. Among them is the tuber of potato (Solanum tuberosum), which undergoes considerable cellular expansion in fulfilling its function of carbohydrate storage. Thus, endoreduplication may play an important role in how tubers are able to accommodate this abundance of carbon. However, the cellular debris resulting from crude nuclear isolation methods of tubers, methods that can be used effectively with leaves, precludes the estimation of the tuber endoreduplication index (EI). This article presents a technique for assessing tuber endoreduplication through the isolation of protoplasts while demonstrating representative results obtained from different genotypes and compartmentalized tuber tissues. The major limitations of the protocol are the time and reagent costs required for sample preparation as well as relatively short lifespan of samples after lysis of protoplasts. While the protocol is sensitive to technical variation, it represents an improvement over traditional methods of nuclear isolation from these large specialized cells. Possibilities for improvements to the protocol such as recycling enzyme, the use of fixatives, and other alterations are proposed.

The protocol described herein is a method for measuring endoreduplication within tubers of potato (Solanum tuberosum). It includes plasmolysis and protoplast extraction steps to decrease the noise and debris in downstream flow cytometric analysis.

分离块茎原生质体流式细胞仪测量 Endoreduplication 的研究

Endoreduplication, the replication of a cell's nuclear genome without subsequent cytokinesis, yields cells with increased DNA content and is associated ...