Azido-PEG2-C2-amine (N3-PEG2-CH2CH2NH2) is a PEG-based PROTAC linker that can be used in the synthesis of PROTACs[1]. Azido-PEG2-C2-amine is also a non-cleavable 2 unit PEG ADC linker used in the synthesis of antibody-drug conjugates (ADCs)[2]. Azido-PEG2-C2-amine is a click chemistry reagent, it contains an Azide group and can undergo copper-catalyzed azide-alkyne cycloaddition reaction (CuAAc) with molecules containing Alkyne groups. Strain-promoted alkyne-azide cycloaddition (SPAAC) can also occur with molecules containing DBCO or BCN groups.