- 1 part Glycerol
- 1 part Water
- Bromophenol blue (to taste)
- Optional: xylene cyanol (to taste)
Note 1: Add base to turn from orange/green to blue. NaOH if you have it or perhaps some EDTA pH 8.0. Alternatively, Tris (50 mM) + EDTA (2 mM) solution can be used instead of water to avoid improper pH issues.
Note 2: “To taste” means that dyes are extremely potent and can easily be overdone. It’s best to approach the addition of dyes very cautiously than to overdo it. If, by chance, the dyes are too concentrated, make more “glycerol + Tris/EDTA” or “glycerol + water” and then add the dye-containing solution to the solutions that don’t contain dye until the color is approximately correct.