Used in bioconjugation reactions, particularly in click chemistry applications. Its amine group allows for easy coupling to carboxylic acids or activated esters, while the DBCO moiety enables copper-free click reactions with azides. Commonly employed in labeling biomolecules such as peptides, proteins, and nucleic acids for imaging, diagnostics, and drug delivery. The C5 spacer provides flexibility and reduces steric hindrance, improving reaction efficiency. Suitable for use in live cells and sensitive biological systems due to its fast kinetics and biocompatibility.