Azido-PEG10-CH2COOH is a PROTAC linker belonging to the PEG category, useful for synthesizing PROTAC molecules. This compound is a click chemistry reagent containing an azide group, allowing it to participate in copper-catalyzed azide-alkyne cycloaddition reactions (CuAAc) with alkyne-containing molecules. Additionally, it can engage in strain-promoted alkyne-azide cycloaddition reactions (SPAAC) with molecules containing DBCO or BCN groups.