Used as a versatile linker in bioconjugation, it facilitates the attachment of biomolecules to surfaces or other molecules, enhancing drug delivery systems. Its PEG4 spacer provides flexibility and solubility, making it ideal for modifying peptides, proteins, and antibodies. Commonly applied in the development of antibody-drug conjugates (ADCs) and targeted therapies, it ensures precise delivery of therapeutic agents to specific cells. Additionally, it plays a role in creating diagnostic tools by enabling the labeling of biomolecules for imaging and detection purposes. Its reactivity with thiol groups allows for efficient and stable conjugation in various biochemical and pharmaceutical applications.