Aminooxy-PEG3-methane is a aminooxy-containing PEG reagent The hydrophilic PEG spacer increases solubility in aqueous media. The aminooxy group is reactive with an aldehyde to form an oxime bond. If a reductant is used, it will form a hydroxylamine linkage. Aminooxy compounds are very reactive and sensitive; they cannot be stored for long term. Immediate use (within 1 week) is highly recommended.