4arm PEG Acetic Acid (4-arm PEG-COOH), MW 40K is a multi-armed PEG derivative with carboxylic acid groups at each end of the four arms, the number of ethylene oxide units in the PEG chain may vary Equal for all arms.
AxisPharm offers 5000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.