Semicarbazide is the chemical compound with the formula OC(NH2)(N2H3). It is a water-soluble white solid. It is a derivative of urea. A thiosemicarbazide is the analog with sulfur atom in place of oxygen atom, with 4-Methyl-3-thiosemicarbazide being a simple example. Semicarbazones are derived by the condensation reaction between a ketone (or aldehyde) and a semicarbazide. Semicarbazide is used in preparing pharmaceuticals including nitrofuran antibacterials (furazolidone, nitrofurazone, nitrofurantoin) and related compounds. Semicarbazide is used as a detection reagent in thin layer chromatography (TLC). Semicarbazide stains α-keto acids on the TLC plate, which must then be viewed under ultraviolet light to see the results. Semicarbazide has been shown to be formed in heat-treated flour containing azodicarbonamide as well as breads made from azodicarbonamide-treated flour.