MitoView™ Blue is a blue fluorescent mitochondrial dye with absorbance/emission at 398/440 nm, suitable for detection by confocal microscopy or flow cytometry using settings for DAPI or Pacific Blue®. The dye is membrane permeable and becomes brightly fluorescent upon accumulation in the mitochondrial membrane. Staining is dependent on mitochondrial membrane potential, and can be used to monitor mitochondrial membrane potential in intact cells. The dye is designed for use in live cells and is not fixable. Note: MitoView Blue can cause phototoxicity to mitochondria during imaging, which causes the dye to leach out of mitochondria into the cytoplasm, so the lowest laser power that gives adequate signal should be used for confocal microscopy. Due to phototoxicity, imaging of MitoView Blue by epifluorescence microscopy is not recommended. If you must use UV excitation to focus on the cells, the exposure should be kept as brief and low intensity as possible. Once the cells are in focus, move to an adjacent field for confocal imaging. Also see our far-red mitochondrial membrane potential dye MitoView 633, our membrane potential-independent green fluorescent mitochondrial dye MitoView Green, and our wide selection of other Membrane and Organelle stains.