Propargyl-PEG1-SS-PEG1-PFP ester is a cleavable 1 unit PEG ADC linker used in the synthesis of antibody-drug conjugates (ADCs)[1]. Propargyl-PEG1-SS-PEG1-PFP ester is a click chemistry reagent, it contains an Alkyne group and can undergo copper-catalyzed azide-alkyne cycloaddition (CuAAc) with molecules containing Azide groups.