MITO-ID^® Membrane potential cytotoxicity kit

• 10X more sensitive than JC-1 with superior aqueous solubility
• Photostable dual-emission dye
• Suitable for time-course studies evaluating intact and compromised mitochondria
• No-wash/No-medium removal
• Separate MITO-ID^® assay is available for detection of mitochondrial mass
• Detects toxicity at lower drug/dose concentrations
• No solvent artifacts as those seen with JC-1 formulation
• Suitable for high-throughput applications 

The MITO-ID^® Membrane  Potential Cytotoxicity Kit measures fluctuations in mitochondrial membrane potential (MMP) utilizing a cationic dual-emission dye that exists as green fluorescent monomers in the cytosol, and accumulates as orange fluorescent J-aggregates in the mitochondria. Mitochondria having a low membrane potential will accumulate low concentrations of dye and will exhibit green fluorescence while more highly polarized mitochondria will exhibit orange-red fluorescence. Cells exhibit a shift from orange to green fluorescence as mitochondrial function becomes increasingly compromised. The kit is a unique HTS assay that monitors mitochondrial membrane potential in real-time without the need for washes or medium removal.

Mechanism of Action
The basic chemical structure of the dye consists of highly conjugated moieties that extensively delocalize a positive charge thus allowing electrophoretic uptake toward the negatively charged matrix phase of the polarized inner mitochondrial membrane. The dye is capable of entering selectively into mitochondria wherein it changes its color reversibly from green to orange as membrane potential increases (dual-emission potential probe). This photophysical property is due to the reversible formation of J-aggregates upon membrane polarization that causes shifts in emitted light from ~530nm (the emission of the monomeric dye) to 590 nm (the emission of the J-aggregate form) when excited at 490 nm. As a consequence, mitochondria having a low membrane potential will accumulate low concentrations of dye and will exhibit green fluorescence while more highly polarized mitochondria will exhibit orange fluorescence.

Mitochondria play a central role in cellular metabolism, bioenergetics, and apoptosis. Decreased mitochondrial function is known to be a major contributor to drug-associated toxicity in various organs. Growing FDA emphasis on evaluating the mitotoxic effects of drug candidates has increased the importance of determining such effects early in the drug development process.