Polysorbate 20, molecular biology reagent

Solubility: Soluble/miscible in water (1g/20 mL) to give a clear yellow solution; miscible with alcohol, dioxane, and ethyl acetate; practically insoluble in liquid paraffin and fixed oils (such as mineral oil).

Sterilization of Solutions: Autoclaving of solutions is not recommended. Sterile filtering is suggested with a 0.22 micron filter. Tween® may need to be warmed to about 40 °C and alternated with portions of hot distilled water while being poured through the filter.

Applications
Polysorbate 20 is typically used as an emulsifying agent for the preparation of stable oil-in-water emulsions, particularly in pharmaceutical applications. It has been used in pre-extraction of membranes to remove peripheral proteins (used at 2% for extraction of membrane-bound proteins). It has been used as a blocking agent on nitrocellulose at a typical concentration of 0.05%.

Product Description
Polysorbate 20 is nonionic surfactant derived from sorbitan ester.

Typical Working Concentration
As a blocking agent on nitrocellulose at a typical concentration of 0.05%. Used at concentration of 2% for extraction of membrane-bound proteins.

Trade Name
Tween® is a registered trademark of Uniqema, a business unit of ICI Americas, Inc.