Cell-based assays for evaluating the functional status of mitochondria are emerging as useful tools for elucidating the role of mitochondrial activity in drug-induced toxicity, the apoptosis cascade and other cellular and biochemical processes. The loss of the mitochondrial membrane potential (MMP) is often associated with early stages of apoptosis. The collapse of MMP coincides with the opening of the mitochondrial permeability transition pores, leading to the release of cytochrome C into the cytosol, which in turn triggers other downstream events in the apoptotic cascade. MITO-ID Membrane Potential Detection Kit measures mitochondrial membrane potential with a cationic dye that fluoresces either green or orange depending upon membrane potential status. Applications: Flow Cytometry, Fluorescence microscopy, Fluorescent detection, HTS .