- Dissolve 70 mg of Commasie blue G-250 in 1 liter of distilled water.
- Stir for 2–4 hours.
- Add 3 ml of concentrated HCl to the dark blue solution.
- Stir for another minute.
- Store in the dark for later use.
- The solution can be stored for weeks up to several months without losing its staining efficiency.