naphthalene blue black CS (acid form)
naphthalene blue black cs (acid form)
A bis(azo) compound that is naphthalene-2,7-disulfonic acid in which the hydrogens at positions 3, 4, 5, and 6 are replaced by (<em>p</em>-nitrophenyl)azo, amino, hydroxy, and (<em>p</em>-sulfophenyl)azo groups, respectively. The trisodium salt is the histological dye 'naphthalene blue black CS'.