4-Arm PEG-SH (MW 20000)

4-Arm PEG-SH (MW 20000) (4-Arm PEG-thiol (MW 20000) ) is a multi-arm PEG derivative with thiol groups at the ends of its four arms. The reactive free thiol, SH, or mercapto groups selectively react with maleimide and surfaces of transition metals such as gold and silver.