The MitoProbe™ JC-1 Assay Kit provides solutions of the membrane-potential-sensitive dye, JC-1, and a mitochondrial membrane-potential disrupter, CCCP, for the study of mitochondrial membrane potential. JC-1 penetrates the cytosol of eukaryotic cells and exhibits potential-dependent accumulation in mitochondria, indicated by a fluorescence emission shift from green (~529 nm) to red (~590 nm). Consequently, mitochondrial depolarization is indicated by a decrease in the red/green fluorescence intensity ratio.