B261 is a multifunctional dye, vital for biological experiments, aiding researchers in observing and analyzing cell structures, tracking biomolecules, evaluating cell functions, distinguishing cell types, detecting biomolecules, studying tissue pathology, and monitoring microorganisms. Its applications span basic scientific research to clinical diagnostics, along with traditional fields like textile dyeing and emerging areas such as functional textile processing, food pigments, and dye-sensitized solar cells.