Aminooxy-PEG1-amine is a chemical reagent containing an aminooxy group and a primary amine. The aminooxy group can react with aldehydes to form oxime bonds, and with reductive agents, it can create hydroxylamine bonds. The amine group can interact with activated NHS esters or carboxylic acids in the presence of the coupling agent EDC. Compounds with aminooxy groups are highly reactive and sensitive, and should not be stored for long periods.