Rhodamine 6G is a highly fluorescent hydrophilic pH-sensitive dye. It is often used as a tracer dye within water to determine the rate and direction of flow and transport. Rhodamine dyes are used extensively in biotechnology applications such as fluorescence microscopy, flow cytometry, fluorescence correlation spectroscopy and ELISA. The dye has a remarkably high photostability and high fluorescence quantum yield. Used as a laser dye and potential mitochondrial probe. The lasing range of the dye is 555 to 585 nm with a maximum at 566 nm. Useful in Pgp efflux assays and has been used to characterize kinetics of MRP1-mediated efflux. Spectral data: lambdaex 528 nm| lambdaem 551 nm (in MeOH).