This work was supported by National Institutes of Health (CA142664).

1. Detection of ROS using carboxy-H2DCFDA
Carboxy-H2DCFDA is non-fluorescent but in the presence of ROS, when this reagent is oxidized, it becomes green fluorescent.
<ol>
 <li>Immediately prior to use, prepare a fresh stock solution of carboxy-H2DCFDA in sterile dimethylsulfoxide (DMSO) or 100% ethanol. Avoid multiple thaw/freeze cycles of your dye.</li>
 <li>Wash the cells with HEPES buffered salt solution (HBSS) or phosphate-buffered saline (PBS) to remove ...

<ol>
	<li>Guzik, T. J., Korbut, R., Adamek-Guzik, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nitric+oxide+and+superoxide+in+inflammation+and+immune+regulation.">Nitric oxide and superoxide in inflammation and immune regulation.</a> J Physiol Pharmacol. 54, 469-487 (2003).</li><li>Perl, A., Gergely, P., Banki, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mitochondrial+dysfunction+in+T+cells+of+patients+with+systemic+lupus+erythematosus.">Mitochondrial dysfunction in T cells of patients with systemic lupus erythematosus.</a> Int Rev Immunol. 23, 293-313 (2004).</li><li>Valko, M., Leibfritz, D., Moncol, J., Cronin, M. T., Mazur, M., Telser, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Free+radicals+and+antioxidants+in+normal+physiological+functions+and+human+disease.">Free radicals and antioxidants in normal physiological functions and human disease.</a> Int J Biochem Cell Biol. 39, 44-84 (2007).</li><li>Droge, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Free+radicals+in+the+physiological+control+of+cell+function.">Free radicals in the physiological control of cell function.</a> Physiol Rev. 82, 47-95 (2002).</li><li>Nakamura, K., Yube, K., Miyatake, A., Cambier, J. C., Hirashima, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Involvement+of+CD4+D3-D4+membrane+proximal+extracellular+domain+for+the+inhibitory+effect+of+oxidative+stress+on+activation-induced+CD4+down-regulation+and+its+possible+role+for+T+cell+activation.">Involvement of CD4 D3-D4 membrane proximal extracellular domain for the inhibitory effect of oxidative stress on activation-induced CD4 down-regulation and its possible role for T cell activation.</a> Mol Immunol. 39, 909-921 (2003).</li><li>Los, M., Droge, W., Stricker, K., Baeuerle, P. A., Schulze-Osthoff, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hydrogen+peroxide+as+a+potent+activator+of+T+lymphocyte+functions.">Hydrogen peroxide as a potent activator of T lymphocyte functions.</a> Eur J Immunol. 25, 159-165 (1995).</li><li>Deem, T. L., Cook-Mills, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vascular+cell+adhesion+molecule+1+(VCAM-1)+activation+of+endothelial+cell+matrix+metalloproteinases:+role+of+reactive+oxygen+species.">Vascular cell adhesion molecule 1 (VCAM-1) activation of endothelial cell matrix metalloproteinases: role of reactive oxygen species.</a> Blood. 104, 2385-2393 (2004).</li><li>Pacher, P., Beckman, J. S., Liaudet, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nitric+oxide+and+peroxynitrite+in+health+and+disease.">Nitric oxide and peroxynitrite in health and disease.</a> Physiol Rev. 87, 315-424 (2007).</li><li>Griendling, K. K., Sorescu, D., Lassegue, B., Ushio-Fukai, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modulation+of+protein+kinase+activity+and+gene+expression+by+reactive+oxygen+species+and+their+role+in+vascular+physiology+and+pathophysiology.">Modulation of protein kinase activity and gene expression by reactive oxygen species and their role in vascular physiology and pathophysiology.</a> Arterioscler Thromb Vasc Biol. 20, 2175-2183 (2000).</li><li>Loh, K., Deng, H., Fukushima, A., Cai, X., Boivin, B., Galic, S., Bruce, C., Shields, B. J., Skiba, B., Ooms, L. M., Stepto, N., Wu, B., Mitchell, C. A., Tonks, N. K., Watt, M. J., Febbraio, M. A., Crack, P. J., Andrikopoulos, S., Tiganis, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reactive+oxygen+species+enhance+insulin+sensitivity.">Reactive oxygen species enhance insulin sensitivity.</a> Cell Metab. 10, 260-272 (2009).</li><li>Goldstein, B. J., Mahadev, K., Wu, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Redox+paradox:+insulin+action+is+facilitated+by+insulin-stimulated+reactive+oxygen+species+with+multiple+potential+signaling+targets.">Redox paradox: insulin action is facilitated by insulin-stimulated reactive oxygen species with multiple potential signaling targets.</a> Diabetes. 54, 311-321 (2005).</li></ol>

Several pathological situations such as inflammatory diseases, cancers, ischemia/reperfusion, and also treatments such as radiation or chemotherapy (i.e cisplatin) induce ROS overproduction. Thus, detecting and measuring ROS levels is important in many basic, pre-clinical and clinical studies. However, ROS have very short half lives and could be complicated to detect. Here, we propose simple tests that are routinely used and widely accepted for the detection of free radical production in mammalian cells.
<p class="j...

<table border="1">
	<tbody>
		<tr>
			<th>
				Name of the reagent</th>
			<th>
				Company</th>
			<th>
				Catalogue number</th>
			<th>
				Comments (optional)</th>
		</tr>
		<tr>
			<td>5-(and-6)-carboxy-2',7'-dichlorofluorescein diacetate (carboxy-DCFDA)</td>
			<td>Molecular Probes</td>
			<td>C369</td>
			<td>control</td>
		</tr>
		<tr>
			<td>carboxy-H2DCFDA</td>
			<td>Molecular Probes</td>
			<td>C400</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Sulfanilamide</td>
			<td>Sigma</td>
			<td>S9251-100G</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>N-1-napthylethylenediamine dihydrochloride</td>
			<td>Sigma</td>
			<td>N9125-10G</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Nitrite standard</td>
			<td>Sigma</td>
			<td>237213-100G</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>GSH/GSSG-Glo Assay</td>
			<td>Promega</td>
			<td>V6612</td>
			<td>To quantify oxidized, reduced or oxidized/reduced glutathione</td>
		</tr>
	</tbody>
</table>

production and detection of reactive oxygen species (ros) in cancers

Reactive oxygen species include a number of molecules that damage DNA and RNA and oxidize proteins and lipids (lipid peroxydation). These reactive molecules contain an oxygen and include H2O2 (hydrogen peroxide), NO (nitric oxide), O2- (oxide anion), peroxynitrite (ONOO-), hydrochlorous acid (HOCl), and hydroxyl radical (OH-).
Oxidative species are produced not only under pathological situations (cancers, ischemic/reperfusion, neurologic and cardiovascular pathologies, infectious diseases, inflammatory diseases 1, autoimmune diseases 2, etc&hellip;) but also during physiological (non-pathological) situations such as cellular metabolism 3, 4. Indeed, ROS play important roles in many cellular signaling pathways (proliferation, cell activation 5, 6, migration 7 etc..). ROS can be detrimental (it is then referred to as "oxidative and nitrosative stress") when produced in high amounts in the intracellular compartments and cells generally respond to ROS by upregulating antioxidants such as superoxide dismutase (SOD) and catalase (CAT), glutathione peroxidase (GPx) and glutathione (GSH) that protects them by converting dangerous free radicals to harmless molecules (i.e. water). Vitamins C and E have also been described as ROS scavengers (antioxidants).
Free radicals are beneficial in low amounts 3. Macrophage and neutrophils-mediated immune responses involve the production and release of NO, which inhibits viruses, pathogens and tumor proliferation 8. NO also reacts with other ROS and thus, also has a role as a detoxifier (ROS scavenger). Finally NO acts on vessels to regulate blood flow which is important for the adaptation of muscle to prolonged exercise 9, 10. Several publications have also demonstrated that ROS are involved in insulin sensitivity 11, 12.
Numerous methods to evaluate ROS production are available. In this article we propose several simple, fast, and affordable assays; these assays have been validated by many publications and are routinely used to detect ROS or its effects in mammalian cells. While some of these assays detect multiple ROS, others detect only a single ROS.

Watch this Scientific Journal Video about Production and Detection of Reactive Oxygen Species ROS in Cancers at JoVE.com

Production and Detection of Reactive Oxygen Species ROS in Cancers

Here we propose simple methods to test and evaluate the presence of reactive oxygen species in cells.

Production and Detection of Reactive Oxygen Species (ROS) in Cancers

Reactive oxygen species include a number of molecules that damage DNA and RNA and oxidize proteins and lipids (lipid peroxydation). These reactive ...

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69.7K visualizações.  Baylor College of Medicine. Aqui nós propor métodos simples para testar e avaliar a presença de espécies reativas de oxigênio nas células.