Hydroxynaphthol Blue; Hydroxy naphthol blue disodium salt; 3-Hydroxy-4-(2-hydroxy-4-sulfo-1-naphthylazo)naphthalene-2,7-disulfonic acid trisodium salt; Hydroxy naphthol blue; Sodium (E)-3-hydroxy-4-((2-hydroxy-6-sulfo-3-sulfonatonaphthalen-1-yl)diazenyl)naphthalene-1-sulfonate; Hydroxynaphthol blue sodium salt; Disodium 3-hydroxy-4-[2-(2-oxo-4-sulfonatonaphthalen-1(2H)-ylidene)hydrazinyl]-7-sulfonaphthalene-2-sulfonate; CAS Number: 165660-27-5; EC number: 264-197-7; MDL number: MFCD00058506; Molecular Formula: C20H12N2O11S3Na2; Molecular Formula: C20H12N2Na2O11S3; Molecular Weight: 598.49;