A composition for detecting blood includes 3,3′, 5, 5′-tetramethylbenzidine, cumene hydroperoxide, and a surfactant. The composition is an aqueous solution. The surfactant is an anionic surfactant or a non-ionic surfactant. The composition is useful for the detection of blood, in particular occult blood in saliva. Also described are methods for detecting blood using the composition, a kit including the composition, and the use of a surfactant to reduce the time taken to detect blood.
