Carbonate-bicarbonate buffer stock (pH 9.2)

1. Prepare a 0.2-M solution of anhydrous sodium carbonate (2.2 g/100 mL).

2. Prepare a 0.2-M solution of sodium bicarbonate (1.68 g/100 mL).

3. Combine 4 mL of carbonate solution from Step 1 and 46 mL of bicarbonate solution from Step 2.

4. Bring to 200 mL with H2O. Final pH will be 9.2.

Use this stock to make 0.05M Carbonate buffer

Ref-Cold Spring Harbor Protocol