Used as a bifunctional crosslinking agent in bioconjugation and polymer chemistry. Its primary application lies in coupling biomolecules such as proteins, peptides, or antibodies with other molecules like drugs, labels, or surfaces. The compound reacts efficiently with primary amines under mild aqueous conditions, forming stable amide bonds at both ends due to its symmetric N-hydroxysuccinimide (NHS) ester groups. This makes it ideal for constructing well-defined conjugates in diagnostic assays, targeted therapeutics, and immobilization of biomolecules on biosensors or solid supports. The polyethylene glycol (PEG) spacer provides water solubility, reduces non-specific binding, and enhances flexibility between linked components, improving bioavailability and performance in biological systems.