About Tris-HCl buffer solution
Tris(hydroxymethyl)aminomethane hydrochloride (Tris-HCl) is a commonly used buffering solution. The role of Tris-HCl in molecular biology is to control the acidity and osmolarity of a solution. Due to its properties, Tris-HCl is often a component of lysis buffers. The pH of the solution is most commonly made between 7.0 and 8.0.
The recipe below is used to prepare a 100 mL 1 M Tris-HCl solution at pH 8.0. It can, however, be tweaked to make the same solution at a desired pH.
|Reagent||Mass / Volume||Final concentration|
|Tris base||12.11 g||1.0 M|
|Distilled H2O||80 mL|
How to make 1 M Tris-HCl pH 8.0
- Weigh out 12.11 g Tris and add to a 100 mL Duran bottle.
- Measure out 80 mL distilled water and add to the Duran bottle.
- Add a magnetic flea and place on a magnetic stirring plate to mix the solution.
- Add a pH meter into the solution to observe the pH.
- Slowly add concentrated hydrogen chloride (HCl) solution using a Pasteur pipette to reduce the pH to 8.0, or another desired pH. Be careful not to add too much at a time, since the pH will change rapidly.
- Once the desired pH has been reached, top up the solution to 100 mL using distilled water.
- To sterilise, autoclave the solution on a liquid cycle (20 min at 15 psi).
Storage of 1.0 M Tris-HCl pH 8.0 solution
Store 1.0 M Tris-HCl pH 8.0 solutions at room temperature (+15oC – +25oC).
Tris base is not classed as a hazardous substance, however, be careful when using HCl during the pH adjustment step. Concentrated HCl solution is an acid as is very corrosive. Always read the material safety data sheet before using it.