Auramine O is an aniline dye used as a disinfectant and an antiseptic agent. It is weakly fluorescing and binds specifically to certain proteins.
Auramine O is a hydrochloride obtained by combining 4,4'-carbonimidoylbis(N,N-dimethylaniline) with one molar equivalent of hydrogen chloride. A fluorescent stain for demonstrating acid fast organisms in a method similar to the Ziehl Neelsen. It also can be used to make a fluorescent Schiff reagent. It has a role as a fluorochrome and a histological dye. It contains an auramine O(1+).