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 traces of the original medium.</li>
 <li>Load the cells with the dye (and the control dye, cf note section). In this assay we used Jurkat, a human leukemia cell line. Use carboxy-H2DCFDA at a final concentration of 1&mu;M in regular culture medium with reduced serum (2%).</li>
 <li>Incubate the cultures for 30 minutes in the dark, in a conventional incubator (37&deg;C, 5% CO2). Discard all unused dye solutions.</li>
 <li>Remove carboxy-H2DCFDA containing medium and wash twice with HBSS or PBS. From this step forward, protect your cells from light.</li>
 <li>Add fresh medium containing your drug of choice to the carboxy-H2DCFDA -loaded cells and incubate as desired. For this example we use H2O2 (0.03%) for 1 hour.</li>
 <li>Assess ROS by immediately analyzing your cells by flow cytometry using the FL1 channel (green fluorescence), or by fluorescence plate reader, or by fluorescence microscopy. The fluorescence can be detected by using excitation and emission wavelengths that are appropriate for green fluorescence.</li>
</ol>
Note: Controls should include carboxy-H2DCFDA-loaded untreated cells and unstained untreated cells. Carboxy-H2DCFDA is known to detect peroxides but could also be oxidized by other ROS. This reagent can also be modified by other means, oxidation insensitive control dye such as 5-(and-6)-carboxy-2',7'-dichlorofluorescein diacetate (carboxy-DCFDA) should therefore be included in the test.
2. Measurement of nitric oxide (NO) production
You will need Sulfanilamide and N-1-napthylethylenediamine dihydrochloride (NED) solutions, and Nitrite standard. This assay is called the Griess assay.
NED solution : Make a 0.1% solution of N-1-napthylethylenediamine dihydrochloride diluted in sterile water.Sulfanilamide solution : Make a 1% solution of sulfanilamide diluted in 5% phosphoric acid. Nitrite Standard: Dilute the 0.1M standard stock sodium nitrite to 100&mu;M in sterile medium, do a serial dilution in the same medium.
Storage Conditions: Store chemicals as directed by manufacturer at room temperature. When reconstituted, NED and Sulfanilamide solutions are stored immediately after use at 4&deg;C, in the dark, and for a maximum of 3 months.
<ol>
 <li>Culture cells in a 96 well plate, use triplicates for each condition, and include proper controls according to your experiments.</li>
 <li>Treat cells to induce NO production. In our experiment we use lipopolysaccharide (LPS) (100 ng/ml) and recombinant IL-4 to treat our cells. In this protocol, we used RAW 264.7, a mouse macrophage cell line (Mouse leukaemic monocyte macrophage cell line).</li>
 <li>On the day of the assay, bring both reagents to room temperature.</li>
 <li>Spin your plate, collect cell supernatants and transfer 50&mu;l to a new 96 well plate. Prepare limiting dilution wells of your standard stock solution to make a standard curve.</li>
 <li>Add 50&mu;l of Sulfanilamide Solution to each sample and control well and mix well.</li>
 <li>Incubate at room temperature for 10 minutes in the dark.</li>
 <li>Add 50&mu;l of N-1-napthylethylenediamine dihydrochloride solution to each sample and control well and mix well.</li>
 <li>Incubate at room temperature for 10 minutes in the dark.</li>
 <li>Measure absorbance immediately using a plate reader with filter of wavelengths between 520nm and 550nm.</li>
</ol>
If you utilize different plate/dish sizes, use 1/1/1 volume for each solution and sample supernatant.
A violet color will appear in the positive wells. Results obtained with the standard will help you check the stability of your solutions.
3. Detection of ROS action: oxidized proteins
A different method to identify the production of ROS is to look at the end results by detecting the oxidation of proteins. Indeed, ROS modify glutathione, an antioxidant that is expressed in most cells and plays a protective role against ROS. Following oxidation by ROS, modification of the reduced glutathione (GSH) results in the sulfhydryl (thiol) group of its cysteine being linked to a second glutathione via a disulfide bridge. This leads to the formation of a dimerized protein (oxidized protein GSSG). GSH can be restored via modification of GSSG by the enzyme glutathione reductase. The increase in the GSSG/GSH ratio reflects oxidative stress. The following assay is based on the detection and quantification of these oxidized proteins. This method is not selective for specific ROS but rather detects the effects of NO, H2O2, O2- and other ROS. Here we measure the total amount of oxidized (GSSG) and reduced (GSH) glutathione using bioluminescent signals.
<ol>
 <li>Seed your cells in a 96 well plate (white/transparent, flat bottoms) as usual. For our experiment, we used 1x104 cells per well for adherent Raw 264.7 and A549 cells and suspension Jurkat cells. Depending on the size of your cells these numbers could be adjusted. We recommend to plate adherent cells the day before the test to allow them to attach to the plate. Enough wells should be prepared for oxidized and reduced protein detection as well as for "medium only" and untreated cells as controls. Use triplicates for all conditions.</li>
 <li>Treat your cells with your drug for the required time. Here we treated Jurkat cells and A549 cells for 1h with H2O2 (at 5mM and 2.5mM respectively). Raw 264.7 cells were treated with 200ng/ml of LPS for 16 h. During this incubation time, bring all your reagents to room temperature (RT). Make all reagents no more than 30 minutes before performing the test. The table below shows the volumes of reagents per well. When possible, it is important to remove the media containing the reducing agent before proceeding with the test.</li>
</ol>
<table border="1">
 <tbody>
 <tr>
 <td rowspan="2"> </td>
 <td colspan="2">Adherent cells</td>
 <td colspan="2">Suspension cells</td>
 </tr>
 <tr>
 <td>Total Glu Lysis</td>
 <td>Oxidized Glu Lysis</td>
 <td>Total Glu Lysis</td>
 <td>Oxidized Glu Lysis</td>
 </tr>
 <tr>
 <td>NEM, 25mM</td>
 <td>none</td>
 <td>0.5&mu;l</td>
 <td>none</td>
 <td>0.5&mu;l</td>
 </tr>
 <tr>
 <td>Luciferin-NT</td>
 <td>1 &mu;l</td>
 <td>1 &mu;l</td>
 <td>1 &mu;l</td>
 <td>1 &mu;l</td>
 </tr>
 <tr>
 <td>Passive Lysis Buffer, 5X</td>
 <td>10&mu;l</td>
 <td>10&mu;l</td>
 <td>10&mu;l</td>
 <td>10&mu;l</td>
 </tr>
 <tr>
 <td>Distilled water</td>
 <td>39.0&mu;l</td>
 <td>38.5&mu;l</td>
 <td>14&mu;l</td>
 <td>13.5&mu;l</td>
 </tr>
 <tr>
 <td>Final volume per well</td>
 <td>50&mu;l</td>
 <td>50&mu;l</td>
 <td>25&mu;l</td>
 <td>25&mu;l</td>
 </tr>
 </tbody>
</table>
<ol start="3">
 <li>Remove medium from wells with adherent cells. Do not remove medium in wells with suspension cells.</li>
 <li>Add reduced glutathione lysis reagent or oxidized glutathione lysis reagent to the corresponding wells and shake for 5 minutes at RT.</li>
 <li>Add the Luciferin generation reagent and incubate for 30 minutes at RT.</li>
 <li>Add the Luciferin detection reagent and incubate for 15 minutes at RT.</li>
 <li>Read the bioluminescent signal at integration time of 0.25-1 second per well using a plate reader luminometer.</li>
</ol>
<table border="1">
 <tbody>
 <tr>
 <td>
 </td>
 <td>
 Adherent cells</td>
 <td>
 Suspension cells</td>
 </tr>
 <tr>
 <td>Cell number per well</td>
 <td>1x104</td>
 <td>1x104</td>
 </tr>
 <tr>
 <td>Cell suspension per well+ drug</td>
 <td>100 &mu;l, to be removed before 3.4</td>
 <td>25&mu;l, not to be removed</td>
 </tr>
 <tr>
 <td>Reduced Glutathione Lysis Reagent</td>
 <td>50 &mu;l</td>
 <td>25&mu;l</td>
 </tr>
 <tr>
 <td>Oxidized Glutathione Lysis Reagent</td>
 <td>50 &mu;l</td>
 <td>25&mu;l</td>
 </tr>
 <tr>
 <td>Luciferin Generation Reagent</td>
 <td>50 &mu;l</td>
 <td>50 &mu;l</td>
 </tr>
 <tr>
 <td>Luciferin Detection Reagent</td>
 <td>100 &mu;l</td>
 <td>100 &mu;l</td>
 </tr>
 </tbody>
</table>
4. Representative Results:
<img alt="Figure 1" src="/files/ftp_upload/3357/3357fig1.jpg" /> 
Figure 1 Detection of ROS using carboxy-H2DCFDA dye. Jurkat cells (human leukemia cell line) treated with H2O2 were compared to non-treated cells. ROS induces the modification of carboxy-H2DCFDA that fluoresces green as detected by flow cytometry, the fluorescent peak in H2O2 treated cells shift compared to the peaks in controls (H2O2 treated cells stained with oxidation insensitive dye and non-treated cells stained with carboxy-H2DCFDA) . Results confirm the presence of ROS in treated cells.
<img alt="Figure 2" src="/files/ftp_upload/3357/3357fig2.jpg" /> 
Figure 2 Detection of NO using Griess reagents. RAW 264.7 cells (mouse macrophage) were treated with LPS and IL-4. A significant increased in NO production was detected in treated cells compared to control untreated cells.
<table border="1">
 <tbody>
 <tr>
 <td>
 Cell lines</td>
 <td>
 Non-treated</td>
 <td>
 Treated</td>
 </tr>
 <tr>
 <td>Raw 264.7</td>
 <td>13.0</td>
 <td>8.3</td>
 </tr>
 <tr>
 <td>A549</td>
 <td>21.6</td>
 <td>10.5</td>
 </tr>
 <tr>
 <td>Jurkat</td>
 <td>5.2</td>
 <td>2.8</td>
 </tr>
 </tbody>
</table>
Table 1 Detection of ROS mediated oxidation of proteins. RAW 264.7 cells were treated with LPS, Jurkat and A549 (human lung cancer) cells were treated with H2O2. Results are expressed as the ratio reduced (GSH)/oxidized (GSSG) glutathione. Lower ratios of glutathione (GSH)/(GSSG) were detected in treated cells compared to control untreated cells, revealing that proteins were more oxidized in treated cells.

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We received the support of Promega for this publication.

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><tbody><tr><td>5-(and-6)-carboxy-2&amp;rsquo;,7&amp;rsquo;-dichlorofluorescein diacetate (carboxy-DCFDA)</td><td>Molecular Probes, Life Technologies</td><td>C369</td><td>control</td></tr><tr><td>carboxy-H&lt;sub&gt;2&lt;/sub&gt;DCFDA</td><td>Molecular Probes, Life Technologies</td><td>C400</td><td></td></tr><tr><td>Sulfanilamide</td><td>Sigma-Aldrich</td><td>S9251-100G</td><td></td></tr><tr><td>N-1-napthylethylenediamine dihydrochloride</td><td>Sigma-Aldrich</td><td>N9125-10G</td><td></td></tr><tr><td>Nitrite standard</td><td>Sigma-Aldrich</td><td>237213-100G</td><td></td></tr><tr><td>GSH/GSSG-Glo Assay</td><td>Promega Corp.</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 ...

production-and-detection-of-reactive-oxygen-species-ros-in-cancers

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69.9K Views.  Baylor College of Medicine. Here we propose simple methods to test and evaluate the presence of reactive oxygen species in cells.

Video: Production and Detection of Reactive Oxygen Species ROS in Cancers

Imaging Approaches to Assessments of Toxicological Oxidative Stress Using Genetically-encoded Fluorogenic Sensors

While oxidative stress is a commonly cited toxicological mechanism, conventional methods to study it suffer from a number of shortcomings, including destruction of the sample, introduction of potential artifacts, and a lack of specificity for the reactive species involved. Thus, there is a current need in the field of toxicology for non-destructive, sensitive, and specific methods that can be used to observe and quantify intracellular redox perturbations, more commonly referred to as oxidative stress. Here, we present a method for the use of two genetically-encoded fluorogenic sensors, roGFP2 and HyPer, to be used in live-cell imaging studies to observe xenobiotic-induced oxidative responses. roGFP2 equilibrates with the glutathione redox potential (EGSH), while HyPer directly detects hydrogen peroxide (H2O2). Both sensors can be expressed into various cell types via transfection or transduction, and can be targeted to specific cellular compartments. Most importantly, live-cell microscopy using these sensors offers high spatial and temporal resolution that is not possible using conventional methods. Changes in the fluorescence intensity monitored at 510 nm serves as the readout for both genetically-encoded fluorogenic sensors when sequentially excited by 404 nm and 488 nm light. This property makes both sensors ratiometric, eliminating common microscopy artifacts and correcting for differences in sensor expression between cells. This methodology can be applied across a variety of fluorometric platforms capable of exciting and collecting emissions at the prescribed wavelengths, making it suitable for use with confocal imaging systems, conventional wide-field microscopy, and plate readers. Both genetically-encoded fluorogenic sensors have been used in a variety of cell types and toxicological studies to monitor cellular EGSH and H2O2 generation in real-time. Outlined here is a standardized method that is widely adaptable across cell types and fluorometric platforms for the application of roGFP2 and HyPer in live-cell toxicological assessments of oxidative stress.

This manuscript describes the use of genetically-encoded fluorogenic reporters in an application of live-cell imaging for the examination of xenobiotic-induced oxidative stress. This experimental approach offers unparalleled spatiotemporal resolution, sensitivity, and specificity while avoiding many of the shortcomings of conventional methods used for the detection of toxicological oxidative stress.

While oxidative stress is a commonly cited toxicological mechanism, conventional methods to study it suffer from a number of shortcomings, including ...

Cancer Research

Flow Cytometric Analysis of Mitochondrial Reactive Oxygen Species in Murine Hematopoietic Stem and Progenitor Cells and MLL-AF9 Driven Leukemia

We present a flow cytometric approach for analyzing mitochondrial ROS in various live bone marrow (BM)-derived stem and progenitor cell populations from healthy mice as well as mice with AML driven by MLL-AF9. Specifically, we describe a two-step cell staining process, whereby healthy or leukemia BM cells are first stained with a fluorogenic dye that detects mitochondrial superoxides, followed by staining with fluorochrome-linked monoclonal antibodies that are used to distinguish various healthy and malignant hematopoietic progenitor populations. We also provide a strategy for acquiring and analyzing the samples by flow cytometry. The entire protocol can be carried out in a timeframe as short as 3-4 h. We also highlight the key variables to consider as well as the advantages and limitations of monitoring ROS production in the mitochondrial compartment of live hematopoietic and leukemia stem and progenitor subpopulations using fluorogenic dyes by flow cytometry. Furthermore, we present data that mitochondrial ROS abundance varies among distinct healthy HSPC sub-populations and leukemia progenitors and discuss the possible applications of this technique in hematologic research.

We describe a method for using multiparameter flow cytometry to detect mitochondrial reactive oxygen species (ROS) in murine healthy hematopoietic stem and progenitor cells (HSPCs) and leukemia cells from a mouse model of acute myeloid leukemia (AML) driven by MLL-AF9.

We present a flow cytometric approach for analyzing mitochondrial ROS in various live bone marrow (BM)-derived stem and progenitor cell populations from ...

Use of Electron Paramagnetic Resonance in Biological Samples at Ambient Temperature and 77 K

The accurate and specific detection of reactive oxygen species (ROS) in different cellular and tissue compartments is essential to the study of redox-regulated signaling in biological settings. Electron paramagnetic resonance spectroscopy (EPR) is the only direct method to assess free radicals unambiguously. Its advantage is that it detects physiologic levels of specific species with a high specificity, but it does require specialized technology, careful sample preparation, and appropriate controls to ensure accurate interpretation of the data. Cyclic hydroxylamine spin probes react selectively with superoxide or other radicals to generate a nitroxide signal that can be quantified by EPR spectroscopy. Cell-permeable spin probes and spin probes designed to accumulate rapidly in the mitochondria allow for the determination of superoxide concentration in different cellular compartments.
In cultured cells, the use of cell permeable 1-hydroxy-3-methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine (CMH) along with and without cell-impermeable superoxide dismutase (SOD) pretreatment, or use of cell-permeable PEG-SOD,&#160;allows for the differentiation of extracellular from cytosolic superoxide. The mitochondrial 1-hydroxy-4-[2-triphenylphosphonio)-acetamido]-2,2,6,6-tetramethyl-piperidine,1-hydroxy-2,2,6,6-tetramethyl-4-[2-(triphenylphosphonio)acetamido] piperidinium dichloride (mito-TEMPO-H) allows for measurement of mitochondrial ROS (predominantly superoxide).
Spin probes and EPR spectroscopy can also be applied to in vivo models. Superoxide can be detected in extracellular fluids such as blood and alveolar fluid, as well as tissues such as lung tissue. Several methods are presented to process and store tissue for EPR measurements and deliver intravenous 1-hydroxy-3-carboxy-2,2,5,5-tetramethylpyrrolidine (CPH) spin probe in vivo. While measurements can be performed at room temperature, samples obtained from in vitro and in vivo models can also be stored at -80 &#176;C and analyzed by EPR at 77 K. The samples can be stored in specialized tubing stable at -80 &#176;C and run at 77 K to enable a practical, efficient, and reproducible method that facilitates storing and transferring samples.

Electron paramagnetic resonance (EPR) spectroscopy is an unambiguous method to measure free radicals. The use of selective spin probes allows for detection of free radicals in different cellular compartments. We present a practical, efficient method to collect biological samples that facilitate treating, storing, and transferring samples for EPR measurements.

The accurate and specific detection of reactive oxygen species (ROS) in different cellular and tissue compartments is essential to the study of ...

Biochemistry

Detection of Total Reactive Oxygen Species in Adherent Cells by 2',7'-Dichlorodihydrofluorescein Diacetate Staining

Oxidative stress is an important event under both physiological and pathological conditions. In this study, we demonstrate how to quantify oxidative stress by measuring total reactive oxygen species (ROS) using 2&#39;,7&#39;-dichlorodihydrofluorescein diacetate (DCFH-DA) staining in colorectal cancer cell lines as an example. This protocol describes detailed steps including preparation of DCFH-DA solution, incubation of cells with DCFH-DA solution, and measurement of normalized intensity. DCFH-DA staining is a simple and cost-effective way to detect ROS in cells. It can be used to measure ROS generation after chemical treatment or genetic modifications. Therefore, it is useful for determining cellular oxidative stress upon environment stress, providing clues to mechanistic studies.

Here, we present a protocol to detect total cellular reactive oxygen species (ROS) using 2&#39;,7&#39;-dichlorodihydrofluorescein diacetate (DCFH-DA). This method can visualize cellular ROS localization in adherent cells with a fluorescence microscope and quantify ROS intensity with a fluorescence plate reader. This protocol is simple, efficient and cost-effective.

Oxidative stress is an important event under both physiological and pathological conditions. In this study, we demonstrate how to quantify oxidative ...

In Vivo Imaging of Reactive Oxygen Species in a Murine Wound Model

The generation of reactive oxygen species (ROS) is a hallmark of inflammatory processes, but in excess, oxidative stress is widely implicated in various pathologies such as cancer, atherosclerosis and diabetes. We have previously shown that dysfunction of the Nuclear factor (erythroid-derived 2)-like 2 (Nrf2)/ Kelch-like erythroid cell-derived protein 1 (Keap1) signaling pathway leads to extreme ROS imbalance during cutaneous wound healing in diabetes. Since ROS levels are an important indicator of progression of wound healing, specific and accurate quantification techniques are valuable. Several in vitro assays to measure ROS in cells and tissues have been described; however, they only provide a single cumulative measurement per sample. More recently, the development of protein-based indicators and imaging modalities have allowed for unique spatiotemporal analyses. L-012 (C13H8ClN4NaO2) is a luminol derivative that can be used for both in vivo and in vitro chemiluminescent detection of ROS generated by NAPDH oxidase. L-012 emits a stronger signal than other fluorescent probes and has been shown to be both sensitive and reliable for detecting ROS. The time lapse applicability of L-012-facilitated imaging provides valuable information about inflammatory processes while reducing the need for sacrifice and overall reducing the number of study animals. Here, we describe a protocol utilizing L-012-facilitated in vivo imaging to quantify oxidative stress in a model of excisional wound healing using diabetic mice with locally dysfunctional Nrf2/Keap1.

In Vivo Imaging of Reactive Oxygen Species in a Murine Wound Model

We describe a non-invasive in vivo imaging protocol that is streamlined and cost-effective, utilizing L-012, a chemiluminescent luminol-analog, to visualize and quantify reactive oxygen species (ROS) generated in a mouse excisional wound model.

The generation of reactive oxygen species (ROS) is a hallmark of inflammatory processes, but in excess, oxidative stress is widely implicated in various ...

Immunology and Infection

Flow Cytometric Measurement Of ROS Production In Macrophages In Response To Fc&#947;R Cross-linking

The oxidative or respiratory burst is used to describe the rapid consumption of oxygen and generation of reactive oxygen species (ROS) by phagocytes in response to various immune stimuli. ROS generated during immune activation exerts potent antimicrobial activity primarily through the ability of ROS to damage DNA and proteins, causing death of microorganisms. Being able to measure ROS production reproducibly and with ease is necessary in order to assess the contribution of various pathways and molecules to this mechanism of host defense. In this paper, we demonstrate the use of fluorescent probes and flow cytometry to detect ROS production. Although widely used, fluorescent measurement of ROS is notoriously problematic, especially with regards to measurement of ROS induced by specific and not mitogenic stimuli. We present a detailed methodology to detect ROS generated as a result of specific Fc&#947;R stimulation beginning with macrophage generation, priming, staining, Fc&#947;R cross-linking, and ending with flow cytometric analysis.

This study demonstrates the use of flow cytometry to detect reactive oxygen species (ROS) production resulting from activation of the Fc&#947;R. This method can be used to assess changes in the antimicrobial and redox signaling function of phagocytes in response to immune complexes, opsonized microorganisms, or direct Fc&#947;R cross-linking.

The oxidative or respiratory burst is used to describe the rapid consumption of oxygen and generation of reactive oxygen species (ROS) by phagocytes in ...

Novel ROS Quantification Using Dihydroethidium in Liver Cancer Cells

High Throughput Screening Assessment of Reactive Oxygen Species (ROS) Generation using Dihydroethidium (DHE) Fluorescence Dye

Reactive oxygen species (ROS) play a key role in the regulation of cellular metabolism in physiological and pathological processes. Physiological ROS production plays a central role in the spatial and temporal modulation of normal cellular functions such as proliferation, signaling, apoptosis, and senescence. In contrast, chronic ROS overproduction is responsible for a wide spectrum of diseases, such as cancer, cardiovascular disease, and diabetes, among others. Quantifying ROS levels in an accurate and reproducible manner is thus essential to understanding normal cellular functionality. Fluorescence imaging-based methods to characterize intra-cellular ROS species is a common approach. Many of the imaging ROS protocols in the literature use 2&#39;-7&#39;-dichlorodihydrofluorescein diacetate (DCFH-DA) dye. However, this dye suffers from significant limitations in its usage and interpretability. The current protocol demonstrates the use of a dihydroethidium (DHE) fluorescent probe as an alternative method to quantify total ROS production in a high-throughput setting. The high throughput imaging platform, CX7 Cellomics, was used to measure and quantify the ROS production. This study was conducted in three hepatocellular cancer cell lines - HepG2, JHH4, and HUH-7. This protocol provides an in-depth description of the various procedures involved in the assessment of ROS within the cells, including - preparation of DHE solution, incubation of cells with DHE solution, and measurement of DHE intensity necessary to characterize the ROS production. This protocol demonstrates that DHE fluorescent dye is a robust and reproducible choice to characterize intracellular ROS production in a high-throughput manner. High throughput approaches to measure ROS production are likely to be helpful in a variety of studies, such as toxicology, drug screening, and cancer biology.

Author Spotlight: High-Throughput Measurement of Intracellular ROS Levels in Hepatocellular Lines

This protocol describes a novel method to quantify intracellular reactive oxygen species (ROS) using dihydroethidium (DHE) as a fluorescence dye probe using a high-throughput screening approach. The protocol describes the methods for quantitative assessment of intracellular reactive oxygen species (ROS) in the three different hepatocellular carcinoma cell lines.

Reactive oxygen species (ROS) play a key role in the regulation of cellular metabolism in physiological and pathological processes. Physiological ROS ...

Bioengineering

Analysis of Oxidative Stress in Zebrafish Embryos

High levels of reactive oxygen species (ROS) may cause a change of cellular redox state towards oxidative stress condition. This situation causes oxidation of molecules (lipid, DNA, protein) and leads to cell death. Oxidative stress also impacts the progression of several pathological conditions such as diabetes, retinopathies, neurodegeneration, and cancer. Thus, it is important to define tools to investigate oxidative stress conditions not only at the level of single cells but also in the context of whole organisms. Here, we consider the zebrafish embryo as a useful in vivo system to perform such studies and present a protocol to measure in vivo oxidative stress. Taking advantage of fluorescent ROS probes and zebrafish transgenic fluorescent lines, we develop two different methods to measure oxidative stress in vivo: i) a &#8220;whole embryo ROS-detection method&#8221; for qualitative measurement of oxidative stress and ii) a &#8220;single-cell&#160;ROS detection method&#8221; for quantitative measurements of oxidative stress. Herein, we demonstrate the efficacy of these procedures by increasing oxidative stress in tissues by oxidant agents and physiological or genetic methods. This protocol is amenable for forward genetic screens and it will help address cause-effect relationships of ROS in animal models of oxidative stress-related pathologies such as neurological disorders and cancer.

Here we report a protocol to measure oxidative stress in living zebrafish embryos. This procedure allows reactive oxygen species (ROS) detection in both whole embryo tissues and single-cell populations. This protocol will accomplish both qualitative and quantitative analyses.

High levels of reactive oxygen species (ROS) may cause a change of cellular redox state towards oxidative stress condition. This situation causes ...

Biology

Quantification of Reactive Oxygen Species Using 2&#8242;,7&#8242;-Dichlorofluorescein Diacetate Probe and Flow-Cytometry in M&#252;ller Glial Cells

The redox balance has an important role in maintaining cellular homeostasis. The increased generation of reactive oxygen species (ROS) promotes the modification of proteins, lipids, and DNA, which finally may lead to alteration in cellular function and cell death. Therefore, it is beneficial for cells to increase their antioxidant defense in response to detrimental insults, either by activating an antioxidant pathway like Keap1/Nrf2 or by improving redox scavengers (vitamins A, C, and E, &#946;-carotene, and polyphenols, among others). Inflammation and oxidative stress are involved in the pathogenesis and progression of retinopathies, such as diabetic retinopathy (DR) and retinopathy of prematurity (ROP). Since M&#252;ller glial cells (MGCs) play a key role in the homeostasis of neural retinal tissue, they are considered an ideal model to study these cellular protective mechanisms. In this sense, quantifying ROS levels with a reproducible and simple method is essential to assess the contribution of pathways or molecules that participate in the antioxidant cell defense mechanism. In this article, we provide a complete description of the procedures required for the measurement of ROS with DCFH-DA probe and flow cytometry in MGCs. Key steps for flow cytometry data processing with the software are provided here, so the readers will be able to measure ROS levels (geometric means of FITC) and analyze fluorescence histograms. These tools are highly helpful to evaluate not only the increase in ROS after a cellular insult but also to study the antioxidant effect of certain molecules that can provide a protective effect on the cells.

Here, we propose a systematized, accessible, and reproducible protocol to detect cellular reactive oxygen species (ROS) using 2&#8242;,7&#8242;-dichlorofluorescein diacetate probe (DCFH-DA) in M&#252;ller glial cells (MGCs). This method quantifies total cellular ROS levels with a flow cytometer. This protocol is very easy to use, suitable, and reproducible.

The redox balance has an important role in maintaining cellular homeostasis. The increased generation of reactive oxygen species (ROS) promotes the ...

Neuroscience

Detecting Reactive Oxygen Species

Reactive oxygen species are chemically active, oxygen-derived molecules capable of oxidizing other molecules. Because of their reactive nature, there are many deleterious effects associated with unchecked ROS production, including structural damage to DNA and other biological molecules. However, ROS can also be mediators of physiological signaling. There is accumulating evidence that ROS play significant roles in everything from activation of transcription factors to the mediation of inflammatory toxicity that kills foreign pathogens and defend the body.In this video we will delve into the associations between ROS, metabolism and disease. After establishing their significance, we will discuss the principles and a protocol of a commonly used methodology for measuring ROS levels in cells: the use of non-fluorescent probes that become fluorescent upon oxidation. Lastly, we will review some current applications of this technique in cell biology research.

Reactive Oxygen Species and Oxidative Stress

Reactive oxygen species are chemically active, oxygen-derived molecules capable of oxidizing other molecules. Because of their reactive nature, there are ...

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

Summary

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Chapters in this video

Imaging Approaches to Assessments of Toxicological Oxidative Stress Using Genetically-encoded Fluorogenic Sensors

Flow Cytometric Analysis of Mitochondrial Reactive Oxygen Species in Murine Hematopoietic Stem and Progenitor Cells and MLL-AF9 Driven Leukemia

Use of Electron Paramagnetic Resonance in Biological Samples at Ambient Temperature and 77 K

Detection of Total Reactive Oxygen Species in Adherent Cells by 2',7'-Dichlorodihydrofluorescein Diacetate Staining

In Vivo Imaging of Reactive Oxygen Species in a Murine Wound Model

Flow Cytometric Measurement Of ROS Production In Macrophages In Response To FcγR Cross-linking

High Throughput Screening Assessment of Reactive Oxygen Species (ROS) Generation using Dihydroethidium (DHE) Fluorescence Dye

Analysis of Oxidative Stress in Zebrafish Embryos

Quantification of Reactive Oxygen Species Using 2′,7′-Dichlorofluorescein Diacetate Probe and Flow-Cytometry in Müller Glial Cells

Detecting Reactive Oxygen Species