O-[2-(Boc-amino)ethyl]-Oμ-(2-carboxyethyl)polyethylene glycol 3,000

t-Boc-Aminooxy-PEG12-acid is a water soluble PEG reagent The terminal carboxylic acid can react with primary amine groups in the presence of activators (e.g. EDC, or HATU) to form a stable bond. The Boc-protected amine can be deprotected under mild acidic conditions.