Sulforhodamine 101 is widely used as a fluorescent dye in biological and biochemical research. It is particularly valuable in cell imaging and microscopy due to its strong fluorescence and photostability. The dye is often employed to label proteins, nucleic acids, and other biomolecules for tracking and visualization in live or fixed cells. It is also utilized in fluorescence-based assays to study cellular processes such as endocytosis, membrane dynamics, and intracellular trafficking. Additionally, Sulforhodamine 101 is a common choice in flow cytometry for cell sorting and analysis. Its compatibility with various excitation and emission filters makes it a versatile tool in fluorescence spectroscopy and multiplexed detection systems.