N3-PEG3-CH2CH2-Boc is a cleavable 3 unit PEG ADC linker used in the synthesis of antibody-drug conjugates (ADCs)[1]. N3-PEG3-CH2CH2-Boc is also a PEG- and Alkyl/ether-based PROTAC linker that can be used in the synthesis of PROTACs[2]. N3-PEG3-CH2CH2-Boc 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.