I have added a final concentration of 0.05% tween20 and 0.5mg/mL BSA to my protein sample; after 3min incubation at RT, the protein solution turns cloudy. This is definitely not the effect of the tween and bsa I have added in, because otherwise the proein stays happily in solution (no precipitation observed). I thought BSA and Tween should not have effect on protein solubility and can't fingure out what has happened. Thanks a lot for the help!!!
What was the composition of the protein buffer, what was the BSA dissolved in, and what was the Tween 20 diluted with? Also, what were the volumes of each solution?
Hi Adam, I have added 0.2uL of 5% Tween 20 (diluted with water from the 10% stock) and 0.5uL of 20mg/mL BSA (dissolved in water) to 19.2uL of my protein solution (stored in 50mM Tris pH7 200mM NaCl 1mM TCEP). I was wondering if the tween could have 'killed' my protein as I have simply left the used bottle at RT on the shelf.
Hi Violet, I strongly recommend against using Tween 20 stored that way. It will oxidize and produce reactive oxygen species that can destroy your protein. I always recommend using Surfact-Amps 20 from Thermo-Fisher Scientific, which is a 10% solution of Tween 20 stored under inert gas. After opening an ampoule, divide the solution into aliquots and store them in the freezer.
Why do you think you need to add 0.05% Tween and 0.5 mg/ml BSA to your protein?
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