The new live imagers MitoMM1/2 for mitochondrial visualization.

Mitochondria are eukaryotic organelles that consist of outer and inner bilayer membranes with a positive potential (H+) in the intermembrane space. This organelle plays an important role in ATP production and apoptosis. To observe the mitochondria in living cells, several fluorescent dyes (such as MitoTracker® [a standard mitochondrial imager] or rhodamine 123) have been developed. However, these reagents are unstable and exhibit a wide range of emission spectra, thereby hampering double staining results. Using recombinant DNA techniques, green or red fluorescent protein (GFP or RFP)-tagged proteins are now available for multi-color labeling of mitochondria. Here, we have discussed the development of the novel mitochondrial live imagers MitoMM1/2, derivatives of ATTO565; furthermore, MitoMM1/2 are sensitive to the membrane potential, resistant to detergents, and the fluorescence of MitoMM1/2 does not overlap with green fluorescence.