Tween®-20 (polysorbate 20) is a polysorbate surfactant commonly used as a blocking and washing agent in Western blotting and other immunostaining assays. Tween®-20 is typically included in blocking buffers and washing buffers at a concentration of 0.1% to reduce non-specific antibody binding.
TWEEN is a registered trademark of Uniqema Americas LLC.
MSDS (PDF): MSDS 22002