Description
In cells undergoing apoptosis, oxidative stress, necrosis, and other cellular processes, the mitochondrial membrane potential (Δψm) can become depolarized. For example, in cells undergoing apoptosis, pro-apoptotic Bcl-2 family proteins cause mitochondrial outer membrane permeabilization (MOMP), resulting in the release of cytochrome C and the subsequent activation of caspase-9 and the apoptotic cascade. MOMP often correlates with the loss of inner mitochondrial membrane potential (Δψm), which can be detected using Δψm-sensitive dyes. These cationic, lipophilic dyes accumulate within the mitochondria of healthy cells, but not within mitochondria that have lost Δψm due to induction of apoptosis or treatment with a mitochondrial uncoupler.
BD Pharmingen™ MitoStatus TMRE (Tetramethylrhodamine ethyl ester) is a fluorescent dye that is readily sequestered by active mitochondria, allowing for flow cytometric or imaging analysis to assess for apoptosis or mitochondrial depolarization. Non-apoptotic or cells with polarized mitochondria will fluoresce red while apoptotic or cells with depolarizard mitochondria will have diminished levels of red fluorescence. MitoStatus TMRE (Tetramethylrhodamine ethyl ester) has an excitation maximum of 549 nm, but is well-excited by both the blue (e.g. 488 nM) and yellow-green (e.g. 561 nM) lasers. It has an emission maximum of 574 nm.