This chemical is primarily used in bioconjugation and labeling applications due to its reactive trans-cyclooctene (TCO) group, which enables efficient and selective reactions with tetrazines via inverse electron-demand Diels-Alder (IEDDA) chemistry. Its PEG3 spacer enhances solubility and reduces steric hindrance, making it suitable for modifying biomolecules like proteins, peptides, and antibodies without compromising their functionality. The amine group allows for further conjugation to carboxylic acids or other reactive groups, facilitating the attachment of fluorescent dyes, drugs, or other functional moieties. It is particularly valuable in targeted drug delivery, bioimaging, and the development of diagnostic probes, where precise and stable labeling is essential.