Cell-permeant MitoTracker probes stain active mitochondria in live cells for labeling and localization in fluorescent cell imaging. Our rosamine-based mitochondrial staining dyes include MitoTracker Orange CMTMRos, a derivative of tetramethylrosamine, and MitoTracker Red CMXRos, a derivative of X-rosamine. MitoTracker Orange CM-H2TMRos and MitoTracker Red CM-H2XRos are reduced, nonfluorescent versions of the rosamine-based MitoTracker dyes that fluoresce upon oxidation. The fluorescent signal from the rosamine-based MitoTracker dyes is retained in the mitochondria even after aldehyde fixation and detergent permeabilization, making these mitochondria dyes flexible for many workflows including applications that require subsequent processing such as immunocytochemistry or in situ hybridization. MitoTrackerRed and Orange are well suited for multicolor labeling experiments because their fluorescence is well resolved from the green fluorescence of other probes.

Benefits of using MitoTracker mitochondria labeling dyes
MitoTracker dyes are provided in vials of 50 μg of lyophilized powder ready for reconstitution. To label mitochondria, live cells are simply incubated with the MitoTracker probe of your choice. The mitochondrial staining dyes passively diffuse across the plasma membrane and accumulate in active mitochondria. The MitoTracker dyes are offered in a range of wavelengths and can be used for mitochondrial localization in multicolor experiments.

Conventional fluorescent stains such as tetramethylrosamine and rhodamine 123 are readily sequestered by active mitochondria and are reversible in dynamic membrane potential measurements as they easily wash out of cells upon loss in membrane potential. In contrast, MitoTracker dyes contain a mildly thiol-reactive chloromethyl moiety so that mitochondrial staining is retained if the mitochondrial membrane potential is lost, allowing many of the MitoTracker dyes to be retained during cell fixation.

Throughout the cell life cycle, mitochondria use oxidizable substrates to produce an electrochemical proton gradient across the mitochondrial membrane (whose potential is negative), resulting in ATP production. MitoTracker dyes are ideal probes for mitochondria staining in experiments studying the cell cycle or processes such as apoptosis and other end point assays. MitoTracker dyes are also available for flow cytometry applications (Cat. Nos. M46750, M46751, M46752, and M46753).

Related products for mitochondrial membrane potential
For studying dynamic mitochondria membrane potential specifically, we recommend using JC-1 (cationic carbocyanine dye, Cat. No T3168) or TMRM (tetramethyl rhodamine methyl ester, Cat. No. I34361) dyes. The MitoProbe JC-1 Assay Kit (Cat. No. M34152) contains the JC-1 dye in addition to the potent mitochondrial membrane-potential disrupter, CCCP, which depolarizes the mitochondrial membrane. These reagents can provide compensatory controls to correctly compensate green-to-red fluorescence ratio. TMRM is used for the detection of dynamic measurement of mitochondrial membrane potential.