Nile Blue Sulfate

Nile Blue Sulfate is a synthetic organic dye also known as Nile Blue. The chemical name is sodium salt of trisodium 5-amino-4-hydroxy-3-(phenylazo)naphthalene-2,7-disulfonic acid.

Nile blue sulfate is obtained by sulfonation of 4-aminonaphthalene-1-sulfonic acid, followed by diazotation and azo coupling with two aniline molecules.

It is a dark blue, odorless powder, highly soluble in water, alcohol and glycerin. In aqueous solutions it has a bright blue color.

Nile blue sulfate is widely used as a dye for dyeing fabrics (especially silk and cotton), paper, leather, hair, as well as in microscopy and histology.