Product Description
4-Arm PEG-carboxylic acid (4-arm PEG-COOH) is a multiarm PEG derivative with carboxylic acid groups at each terminal of the four arms connected to one pentaerythritol core. There is a methylene (CH2) linkage between PEG and the COOH group, often called acetic acid (AA) or carboxyl methyl (CM). More details can be found at the FAQ webpage. PEG acid can be used to react with amine groups with peptide coupling reagents such as NHS and DCC, EDC.
