Widely used in biochemistry and molecular biology for protein labeling and detection. Enables reversible biotinylation of proteins due to the disulfide (SS) linker, allowing release of biotinylated molecules under reducing conditions. Commonly applied in cell surface protein labeling, where it biotinylates exposed lysine residues on membrane proteins. The biotin tag facilitates strong binding to streptavidin-based purification systems, enabling protein isolation, detection, or pull-down assays. Ideal for experiments requiring elution of captured proteins by breaking the disulfide bond with reducing agents like DTT or β-mercaptoethanol. Also used in crosslinking studies and receptor internalization assays.