TMRE (Tetramethylrhodamine ethyl ester, perchlorate) and TMRM (70017) are preferred dyes for quantitative measurements of membrane potentials using the Nernst equation. The dyes do not form aggregates in cell membranes and have minimal interaction with membrane proteins. Thus, the transmembrane distribution of the dyes is directly related to the membrane potential according to the Nernst equation. Biotium also offers TMRE, 2 mM in DMSO (70005) as a ready to use stock solution.
λEx/λEm (MeOH) = 549/574 nm
Red solid soluble in DMSO, DMF or EtOH
Store at 4°C and protect from light