Azido-PEG3-Ala-Boc is widely used in bioconjugation and click chemistry applications. Its azide group enables efficient coupling with alkyne-functionalized molecules via copper-catalyzed azide-alkyne cycloaddition (CuAAC), making it valuable for labeling, modifying, or crosslinking biomolecules such as proteins, peptides, and nucleic acids. The Boc (tert-butyloxycarbonyl) group serves as a protective moiety for the amine functionality, allowing selective deprotection and further functionalization. The PEG3 spacer enhances solubility and reduces steric hindrance, facilitating reactions in aqueous environments. This compound is particularly useful in drug development, targeted delivery systems, and the synthesis of complex biomolecular architectures.