Prussian blue, also known as ferric ferrocyanide, is a versatile compound with applications in medicine, laboratory staining, art, and technology. In medicine, it is widely used as an antidote for heavy metal poisoning, particularly thallium and radioactive cesium, by binding to these metals in the gastrointestinal tract, preventing absorption into the bloodstream, and promoting excretion. It is also employed as a biological stain in histology and pathology to detect ferric iron in tissues via the Prussian blue reaction. In the field of art, it serves as a stable deep blue pigment in paints, inks, and prints. Furthermore, its unique electrochemical properties make it valuable in electrochromic devices, sensors, batteries (such as Prussian blue analogues in energy storage), and imaging/diagnostic applications. Additionally, it is used in water treatment to remove heavy metals like cesium.