27072-45-3 28325-37-3 29792-10-7 3',6'-Dihydroxy-5(or 6)-isothiocyanatospiro(isobenzofuran-1(3H),9'-(9H)xanthene)-3-one 64937-10-6 EINECS 248-207-7 FITC Fluorescein isothiocyanate Fluorescein-5(or 6)-isothiocyanate Spiro(isobenzofuran-1(3H),9'-(9H)xanthen)-3-one, 3',6'-dihydroxy-5(or 6)-isothiocyanato-