is combined with silver nitrate to produce silver iodide ( ), a key component in film photography. Some disinfectants and hair care chemicals include . In biomedical research, is also utilised as a fluorescence quenching agent, which takes use of the iodide ion's collisional quenching of luminous molecules. However, adding at M-mM doses to numerous fluorophores increases fluorescence intensity, and iodide works as a fluorescence enhancer.