|Phthalocyanin dyes have the general formula to the right.
At the point marked X various groups are attached.
These vary with each dye.
The phthalocyanine dyes are few in number, but those few are commonly used. Alcian blue is employed in one of the standard methods for acid mucopolysaccharides. Luxol fast blue is used to demonstrate myelin.
R. D. Lillie.
Conn's Biological Stains
Williams & Wilkins, Baltimore, MD., U.S.A.