Polyoxyethylenesorbitan Monooleate (Tween 20)

Tween-20 is a polysorbate surfactant whose stability and relative non-toxicity allow it to be used as a detergent and emulsifier in a number of domestic, scientific, and pharmacological applications. It is a polyoxyethylene derivative of sorbitan monolaurate, and is distinguished from the other members in the Tween range by the length of the polyoxyethylene chain. The commercial product contains a range of chemical species. Appearance: Yellow to amber viscous liquid. Hydroxyl Number: 96-108, Water (KF): <3%, Specific Gravity (25°C): 1.095, Acid Value: <2.2mg KOH/g, Saponification Value: <50mg KOH/g, Residual Solvents (1, 4-Dioxane): <0.001%, RNase, DNase: None Detected, Biological applications: Tween 20 has a broad range of applications. For example, it is used: to stabilize purified protein derivative (PPD) solution, used in skin testing for tuberculosis exposure, as a blocking agent in immunologic assays, such as Western blots and ELISA and as a solubilizing agent of membrane proteins for lysing mammalian cells, at a concentration of 0.05 to 0.5%.