Dihydrorhodamine 123 | CAS 109244-58-8

Dihydrorhodamine 123 is a widely used redox-sensitive fluorescent dye that serves as a cell-permeable probe for reactive oxygen species-related oxidative processes. In its reduced form, it exhibits fluorescence after oxidation, enabling visualization and quantitative readouts of oxidative stress in biological assays. Its excitation and emission properties make it compatible with common fluorescence microscopy and plate-reader workflows used in chemical biology, cell biology, and assay development.

1. Oxidative Stress Imaging

Dihydrorhodamine 123 is frequently used in fluorescence microscopy to monitor intracellular oxidative stress dynamics in cultured cells. Researchers employ it to track stimulus-dependent increases in oxidizing equivalents by converting the dye into a fluorescent oxidation product, allowing spatially resolved imaging of oxidative responses across cell populations. This application is common in mechanistic studies of redox signaling, antioxidant screening workflows, and comparative experiments where oxidative burden is expected to change over time.

2. Flow Cytometry ROS Assays

Dihydrorhodamine 123 supports quantitative flow cytometry measurements of oxidative stress at the single-cell level. In this workflow, cells are incubated with the dye and analyzed by fluorescence intensity to compare oxidative status across experimental conditions, including treatment time courses and dose-response studies in redox biology. The readout is typically used to generate population statistics (e.g., shifts in fluorescence-positive fractions and intensity distributions) that are well suited for high-throughput screening formats and mechanistic comparisons.

3. Plate-Based Fluorescence Screening

Dihydrorhodamine 123 is also used in plate-reader fluorescence assays for measuring oxidative responses in a format compatible with multiwell automation. Assay developers use the dye to quantify oxidation-driven fluorescence changes in cell-based or cell-free oxidative systems, supporting screening of compounds that modulate redox balance. This application is particularly useful when researchers need robust, scalable fluorescence readouts to rank conditions by relative oxidative activity while maintaining compatibility with standard excitation/emission measurement setups.

4. Mitochondrial Redox Studies

Dihydrorhodamine 123 is commonly applied to investigate mitochondrial-associated oxidative processes by leveraging its uptake and accumulation behavior in cellular compartments under oxidative conditions. In microscopy and imaging-based studies, researchers use the resulting fluorescence pattern to assess how experimental perturbations alter redox state in mitochondria-enriched regions. This approach is often integrated with co-staining strategies for mitochondrial markers to correlate oxidative fluorescence with organelle localization in redox signaling investigations.