Used as a fluorescent probe to study mitochondrial function and membrane potential in live cells due to its ability to accumulate in active mitochondria. Commonly applied in cell biology and toxicology research to assess cell viability, apoptosis, and mitochondrial activity. Also employed in flow cytometry and fluorescence microscopy for cell tracking and dye retention assays. Serves as a substrate in studies involving multidrug resistance proteins, particularly P-glycoprotein, to evaluate efflux mechanisms in cancer cells. Additionally used in environmental science as a tracer dye for monitoring water flow and detecting leaks in complex systems.