Disodium 4,4'-diisothiocyanato-2,2'-stilbenedisulfonate hydrate (DIDS) is a potent, irreversible inhibitor of anion transport proteins, such as the band 3 anion exchanger (AE1) and other chloride channels. It covalently binds to lysine residues on these proteins, blocking the exchange of anions like chloride and bicarbonate across cell membranes. Widely used in biochemical and physiological research, DIDS is essential for studying membrane transport mechanisms in red blood cells, renal physiology, epithelial tissues, and cystic fibrosis transmembrane conductance regulator (CFTR) function. Its specificity makes it valuable for investigating ion homeostasis, cellular pH regulation, and transport-related diseases.