N-(Aminoethyl)-8-naphthylamine-1-sulfonic acid sodium (1,8-EDNAS sodium) serves as a multifunctional dye with diverse applications in both scientific and industrial fields. Within biological experiments, this dye enables researchers to investigate cell structures, track biomolecules, assess cell functions, identify various cell types, detect biomolecules, examine tissue pathology, and monitor microorganisms. It is employed extensively in fundamental scientific research and a broad array of clinical diagnostics. Beyond biological uses, 1,8-EDNAS sodium is also integral in traditional sectors like textile dyeing and in innovative areas including functional textile processing, food pigments, and dye-sensitized solar cells.