Tween is a non-ionic viscous liquid often used as a surfactant for dispersing hydrophobic particles in aqueous solutions and as a non-ionic detergent for selective protein extraction and isolation of nuclei from mammalian cell lines. Bio-compatible surfactants, Tween 80 and Tween 20 are often used for placing polyethylene
microspheres in suspension.
TWEEN 80 is a polyethylene sorbitol ester, also know as Polysorbate 80, PEG (80) sorbitan monooleate, polyoxyethylenesorbitan monooleate. TWEEN 80 is widely used in biochemical applications including: solubilizing proteins, isolating nuclei from cells in culture, growing of tubercule bacilli, and emulsifying and dispersing substances in medicinal and food products. It has little or no activity as an anti-bacterial agent except it has been shown to have an adverse effect on the antibacterial effect of methyl paraben and related compounds. Polysorbates have been reported to be incompatible with alkalis, heavy metal salts, phenols, and tannic acid. They may reduce the activity of many preservatives.
TWEEN 20 is a polyoxyethylene sorbitol esteris, a frequently used member of the polysorbate family. These have been used as emulsifying agents for the preparation of stable oil-in-water emulsions. TWEEN 20 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 for membrane based immunoassays at a typical concentration of 0.05%. TWEEN 20 can be used for lysing mammalian cells at a concentration of 0.05 to 0.5%.
For Laboratory Use Only. Not for drug, household or other uses.
TWEEN 80 is miscible in water (0.1 ml/ml) yielding a clear to slightly hazy faint yellow solution. It is reported to be miscible with alcohol, cottonseed oil, corn oil, ethyl acetate, methanol, and toluene, but insoluble in mineral oil. The pH of a 1% aqueous solution is 5.5-7.2.
TWEEN 20 is miscible in water (100 mg/ml), yielding a clear, yellow solution. It is also miscible with alcohol, dioxane, and ethyl acetate; and is practically insoluble in liquid paraffin and fixed oils.
The products are not sterile. Autoclaving of solutions is generally not advised. Sterile filtration is more easily done if the liquid is warmed to about 40°C and alternate portions of hot distilled water and TWEEN 80 are poured through the 0.22 μm filter. The TWEEN 80 will blend and remain in solution.
As Tween products are very viscous we recommend diluting to <0.1% with DI
water (heated to ~80C) and then incubating (soaking) the spheres in the
solution at room temperature for at least 6 hrs.
Please refer to the protocol for dispersing polyethylene microspheres in aqueous solutions.