Azido-PEG10-propargyl is a PROTAC linker belonging to the PEG class, suitable for synthesizing PROTAC molecules. It features an azide group, enabling copper-catalyzed azide-alkyne cycloaddition reaction (CuAAC) with molecules containing alkyne groups. Additionally, it can undergo strain-promoted alkyne-azide cycloaddition (SPAAC) with molecules that have DBCO or BCN groups.