Acid fuchsin is made from basic fuchsin homologues by the addition of sulfonic groups. There are four of these compounds, each of which could have up to three sulfonic groups attached, making twelve possible chemicals. Although there may be slight differences in their properties they are all satisfactory. Commercial Acid fuchsin is probably a variable mixture.

It is used in the Van Gieson method in conjunction with picric acid to demonstrate collagen fibers red and in Masson's trichrome to color smooth muscle in contrast to collagen. It is less commonly used in a method for mitochondria.