Amino-PEG5-acid is a PEG compound with an amino group with a terminal carboxylic acid group. The hydrophilic PEG spacer increases solubility in aqueous media. Amine group is reactive with carboxylic acids, activated NHS esters, carbonyls (ketone, aldehyde) etc. 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. Reagent grade, for research purpose. Please contact us for GMP-grade inquiries.