Tris

Tris is a common buffering agent and is short for tris[hydroxymethyl]aminomethane (C₄H₁₁NO₃).

• The formula weight is 121.14
• The pKa of Tris is 8.3
• dpK_a/dT is -.028
• A buffer at pH 6.8 at 25°C will have a pH of 6.46 at 37°C
  • Note that adding HCl during titration will affect the temperature of the solution
• Dilution by a factor of 10 will reduce the pH by 0.1 pH units.