Also Called: 1,5-Naphthalenedisulfonic acid, 3-[[4-[[4-[(6-amino-1-hydroxy- 3-sulfo-2-naphthalenyl)azo]-6-sulfo-1-naphthalenyl ]azo]-1-naphthalenyl]azo]-, tetrasodium salt;direct blue 71;1,5-Naphthalenedisulfonic acid, 3-[[4-[[4-[(6-amino-1-hydroxy-3-sulfo-2-naphthalenyl)azo]-6-sulfo-1-naphthalenyl]azo]-1-naphthalenyl]azo]-, tetrasodium salt;1,5-Naphthalenedisulfonic acid, 3-[2-[4-[2-[4-[2-(6-amino-1-hydroxy-3-sulfo-2-naphthalenyl)diazenyl]-6-sulfo-1-naphthalenyl]diazenyl]-1-naphthalenyl]diazenyl]-, sodium salt (1:4)