Used in bioconjugation for the preparation of antibody-drug conjugates (ADCs). It acts as a crosslinking agent that enables the attachment of drugs to antibodies through sulfhydryl groups. The reagent reacts with primary amines on proteins to form stable amide bonds, while its pyridyldithio group allows for controlled disulfide bond formation with thiol-containing molecules. This makes it ideal for creating stable yet cleavable linkages in targeted therapeutics. Commonly used in the development of diagnostic probes and therapeutic conjugates due to its selective reactivity and moderate spacer arm length, which helps reduce steric hindrance.