Pontamine sky blue 5B (acid form)
pontamine sky blue 5b (acid form)
A ring assembly consisting of two 5-amino-4-hydroxy-3-[(2-methoxyphenyl)diazenyl]naphthalene-2,7-disulfonic acid units joined by a 4,4'-linkage. The tetrasodium salt is the histological dye 'Pontamine sky blue 5B'.