Chromoxane cyanin R, when used with an iron alum mordant, forms a lake which is valued as a substitute for hematoxylin in the H&E stain. Care should be taken with its identification as the supplying companies use eriochrome cyanin R and alizarol cyanin R as its names, but Conn applies these two names to another, closely related dye, CI 43810. It can also be used for the detection of some metals in tissue.