How to Prepare 50x TAE Buffer Stock

1. 1In a fume hood, add ~800 mL distilled water to a 1L beaker and place on magnetic stirrer
2. 2Slowly add 242.28 g Tris base while stirring until dissolved (solution will become warm)
3. 3Add 18.61 g EDTA and stir. If EDTA does not dissolve, add NaOH pellets one at a time until clear
4. 4Working in fume hood, slowly add 57.1 mL glacial acetic acid dropwise while stirring vigorously
5. 5Allow solution to cool to room temperature (pH will stabilize around 8.5)
6. 6Transfer to 1L volumetric flask and dilute to final volume with distilled water
7. 7Mix thoroughly and verify pH is 8.3-8.5 (adjust with small amounts of acetic acid or NaOH if needed)

Final pH should be 8.3-8.5. If needed, adjust with small amounts of glacial acetic acid (to lower) or NaOH solution (to raise). pH adjustment is usually not required if components are measured accurately.

Autoclave at 121°C, 15 psi for 25-30 minutes. Allow to cool before storing. Alternatively, filter sterilize through 0.22 μm filter if autoclaving is not available.

LEVEL 2 SAFETY: Nitrile gloves required, lab coat, safety glasses, fume hood mandatory for glacial acetic acid handling. Glacial acetic acid is corrosive and vapors cause respiratory irritation. Tris-acetic acid reaction is exothermic. EDTA powder can be irritating - avoid inhalation.

Store at room temperature in tightly sealed container. Tris is hygroscopic - moisture absorption will alter concentration. Solution is stable for 1 year if stored properly. Working solutions (1x TAE) should be prepared fresh for best results.