Tris-HCl
For a 1 M solution, dissolve 121.1 g of Tris base in 800 ml of H2O. Adjust the pH to the desired value by adding concentrated HCl.
| pH | HCl |
| 7.4 | 70 ml |
| 7.6 | 60 ml |
| 8.0 | 42 ml |
Allow the solution to cool to room temperature before making final adjustments to the pH. Adjust the volume of the solution to 1 liter with H2O. Dispense into aliquots and sterilize by autoclaving.
If the 1 M solution has a yellow color, discard it and obtain Tris of better quality. The pH of Tris solutions is temperature-dependent and decreases approx. 0.03 pH units for each 1°C increase in temperature. For example, a 0.05 M solution has pH values of 9.5, 8.9, and 8.6 at 5′C, 25′C, and 37°C, respectively.
