RNA Isolation: Does Trizol Reagent contain water? If not, where does water in the 'aqueous phase' come from?
My guess: TRIzol® contains water.
TRIzol® is a "monophasic" solution of phenol, guanidine isothiothiocyanate, and other proprietary components.
Nowhere in the company literature, patents, or MSDS sheets are the words "water" or "aqueous" found.
Yet, the reagent is buffered, so there is probably an aqueous component.
Furthermore, recipes for homemade "TRI" use components such as pH 7.0 buffer, water-saturated phenol, and aqueous solutions of guanidinium thiocyanate, sodium citrate, laurylsarcosine, and mercaptoethanol.
As you say, where does the water in the aqueous phase come from, if not from the reagent?