Description

• General description: Tween 20 is a polyoxyethylene sorbitol ester that belongs to the polysorbate family. It is a nonionic detergent having a molecular weight of 1,225 daltons, assuming 20 ethylene oxide units, 1 sorbitol, and 1 lauric acid as the primary fatty acid. The ethylene oxide subunits are responsible for the hydrophilic nature of the surfactant, while the hydrocarbon chains provide the hydrophobic environment. Sorbitol forms the backbone ring to which the ethylene oxide polymers are attached.[1]
• Application: TWEEN 20 has been used in staining buffer for in situ hybridization.[2] It has also been used to prevent non-specific adsorption of proteins to coverslip during sample preparation for FRET (Förster resonance energy transfer) experiments.[3]
• Caution: TWEEN 20 may not be stable to autoclaving, particularly with metal cations in buffer solutions. Autoclaving is not recommended without testing for changes in properties. TWEEN 20 is heat sensitive and will darken when exposed to elevated temperatures. Polysorbates have been reported to be incompatible with alkalis, heavy metal salts, phenols, and tannic acid. They may also reduce the activity of many preservatives. Aqueous solutions of polysorbates undergo autoxidation during storage, with changes being catalyzed by light, increased temperature, and copper sulfate.
• Preparation Note: TWEEN 20 is miscible in water (100mg/mL), yielding a clear, yellow solution. It is also miscible with alcohol, dioxane, and ethyl acetate. TWEEN 20 is insoluble in liquid paraffin and fixed oils.
• Legal Information: TWEEN is a registered trademark of Croda International PLC