Used in bioconjugation for labeling biomolecules such as proteins, peptides, and antibodies without the need for copper catalysts. Its DBCO group reacts rapidly and selectively with azides through strain-promoted alkyne-azide cycloaddition (SPAAC), making it ideal for click chemistry applications in live cells and complex biological environments. The NHS ester reacts efficiently with primary amines to form stable amide bonds, enabling straightforward attachment to lysine residues or N-termini of proteins. Commonly used in fluorescent labeling, drug delivery systems, and surface functionalization of nanoparticles and biosensors. Suitable for multi-step labeling strategies due to its bioorthogonality and minimal interference with biological functions.