Dithizone or diphenylthiocarbazone has been around for over 60 years. It is an organic compound containing sulfur and is used in chemical analysis and other applications. It is known as a good ligand, because it has the capacity to bind with metals like copper, cobalt, lead, mercury and zinc to form coordinate complexes.
Dithizone has many research and pharmacologicial uses, including determining the purity level of human pancreatic islet preparations that will be transplanted into type 1 diabetes patients. When used for this purpose, Dithizone stains the beta cells of islets red by binding with zinc ions in the beta cells. When exposed to light the red cells are easily visible. It does not affect exocrine tissue because exocrine tissue does not bind Dithizone. Since it is a chelating agent, Dithizone may also be used as an antidote for neutralizing toxic metals and testing for heavy metals in biologic samples and water.