Propargyl-PEG5-amine is a non-cleavable ADC linker used in the synthesis of antibody-drug conjugates (ADCs). Propargyl-PEG5-amine is a PEG-based PROTAC linker can be used in the synthesis of PROTACs.In Vitro: ADCs are comprised of an antibody to which is attached an ADC cytotoxin through an ADC linker.PROTACs contain two different ligands connected by a linker; one is a ligand for an E3 ubiquitin ligase and the other is for the target protein. PROTACs exploit the intracellular ubiquitin-proteasome system to selectively degrade target proteins.