How to Make Tris Buffer Solution

How to Make Tris Buffer Solution

Chemical structure os TRIS
Klaus Hoffmeier/Wikimedia Commons/Public Domain

Tris has a pKa of 8.1 so Tris buffer is made at pH 7 to pH 9. You can prepare this buffer at any concentration and any volume and use it to prevent large swings in the pH of a solution.

Tris Buffer Materials

  • TRIS powder
  • Hydrochloric acid
  • Distilled water
  • pH meter
  • Glassware

How to Prepare Tris Buffer

  1. You need to determine what concentration (molarity) and volume of Tris buffer you want to make. Once you have decided what you are making, calculate the number of moles of Tris that are required by multiplying the molar concentration of buffer by the volume of buffer being made. ​​
    moles of Tris = mol/L x L
  1. Next, determine how many grams of Tris this is by multiplying the number of moles by the molecular weight of Tris (121.14 g/mol).​
    grams of Tris = (moles) x (121.14 g/mol)
  2. Dissolve the Tris into distilled deionized water, 1/3 to 1/2 of your desired final volume.
  3. Mix in HCl (e.g., 1M HCl) until the pH meter gives you the desired pH for your Tris buffer solution.
  4. Dilute the buffer with water to reach the desired final volume of solution.