Azido-PEG8-acid is a aqueous soluble PEG linker containing an azide (N3) and a terminal carboxylic acid (CO2H) group. The azide group can react with alkyne, BCN, DBCO via Click Chemistry to yield a stable triazole linkage. The terminal carboxylic acid can react with primary amine groups in the presence of activators (e.g. EDC, or HATU) to form a stable amide bond.
