Used in bioconjugation processes to link proteins, antibodies, or peptides with other molecules such as drugs, enzymes, or fluorescent labels. Its primary application is in the development of antibody-drug conjugates (ADCs) where it acts as a crosslinker with a spacer arm that provides flexibility and accessibility. The sulfo group enhances water solubility, making it ideal for reactions in aqueous environments without the need for organic solvents. Commonly used in immunoassays, targeted therapy research, and diagnostic probe preparation due to its ability to form stable thioether bonds with sulfhydryl groups after activation.