TAE recipe
Tri-actate-EDTA solution
Link to TBE recipe
Link to About buffer solutions
Stock solution, 50X TAE
To 800 mL (approx) distilled water on a stir plate*, add
- Tris base, 242 g
- Glacial Acetate acid, 55 g
- EDTA, 70.4 g (or 40 mL of 0.5 M EDTA, pH 8.0)
- Fill to final volume of 1 (one) Liter.
* heating may help reduce turbidity to achieve a clear solution more rapidly than RT.
Working solution, 1X TAE
from dry ingredients
- Tris base, 10.8 g
- Boric acid, 5.5 g
- EDTA, 7.4 g (or 4.0 mL of 0.5 M EDTA solution, pH 8.0)
- Fill to final volume of 1 (one) Liter.
from 10X TBE stock solution
Simple dilution problem. For True or False. For 1X working solution, then 1:10 dilution, or one volume 10X stock solution plus nine volumes water.
There are 5 questions in this handout
We use TAE (Tris-Acetate-EDTA) as our buffer solution
| Molarity | Name | Molecular weight (grams) | Density (g/ml) | pKa at  |
| 1.0 | Tris | 121.14 | 1.328 | 8.3 |
| 1.0 | Glacial acetic acid | 60.05 | 1.05 | 4.76 |
| 0.5 | EDTA | 292.24 | 0.86 | 1.782 |
I will provide you with a powder of combined EDTA, Tris, and glacial acetic acid. To make your stock solution, all you have to do is add an amount of the powder (or liquid) into water, mix to dissolve, and you are ready to go. For TAE I will want you to be able to make a 5X solution, then from that stock solution, enough 1X solution to make your gels and provide 1X running buffer for your electrophoresis.
It is useful to work from first principles however, so as a requirement for next week’s quiz, I want you to be able to make a one liter, 1X TAE solution with the following concentrations:
| Chemical | Molarity |
| Tris | 0.089 |
| Glacial acetic acid | 0.020 |
| EDTA | 0.002 |
How many grams of Tris do you add __________________________?
How many mL of glacial acetic acid do you add _______________________?
How many grams of EDTA do you add _________________________?
EDTA is often hard to work with, so often people set up a 0.5 Molar stock solution of EDTA in 200 ml of water. You then use NaOH to adjust the pH to 8.0 and add water to bring the total volume to 500 ml.
How many grams of EDTA do you add to make a 500 ml, 0.5 Molar stock solution? _____________________________
Given you have an 0.5M stock solution of EDTA, what volume of this stock solution would you add for your one liter 1X TAE solution in place of dry weight of EDTA__________________________________________ ?