Used in bioconjugation processes, particularly in the development of antibody-drug conjugates (ADCs) and targeted therapeutics. Its structure enables efficient linking of targeting moieties, such as antibodies, to payloads like drugs or imaging agents. The PEG2 spacer enhances solubility and improves the pharmacokinetic profile of the conjugate by reducing aggregation and increasing circulation time. Commonly applied in pharmaceutical research for constructing stable, water-soluble conjugates with controlled release properties. Also utilized in diagnostic probes and targeted delivery systems where precise coupling and reduced non-specific binding are critical.