Amino-PEG12-C2-azide is a PROTAC linker of the PEG class, utilized in the synthesis of PROTAC molecules. It acts as a click chemistry reagent and features an azide group that can engage in copper-catalyzed azide-alkyne cycloaddition reactions (CuAAC) with molecules containing alkyne groups. Additionally, it participates in strain-promoted azide-alkyne cycloaddition (SPAAC) reactions with molecules that possess either DBCO or BCN groups.