Used in bioconjugation processes to link proteins or peptides with other molecules, particularly in the development of antibody-drug conjugates (ADCs). Its main advantage lies in enabling site-specific conjugation through thiol-disulfide exchange chemistry, where the SPDP portion introduces a disulfide bond that can be cleaved under reducing conditions, allowing controlled release of the payload. The NHS carbonate group reacts efficiently with primary amines on biomolecules, forming stable amide bonds. This dual functionality makes it valuable for creating well-defined conjugates in therapeutic and diagnostic applications. Commonly applied in targeted drug delivery systems and labeling of proteins for immunoassays or imaging.