Widely used in biological imaging due to its bright green fluorescence and high photostability. Commonly employed in fluorescence microscopy to label proteins, nucleic acids, and other biomolecules for visualization in live and fixed cells. Frequently conjugated to antibodies, peptides, or secondary reagents for use in immunofluorescence, flow cytometry, and in situ hybridization. Its excellent water solubility and low toxicity make it suitable for intracellular staining and real-time tracking of cellular processes. Also used in calcium sensing and membrane potential assays when combined with appropriate quenching or targeting moieties.