0.5 M EGTA (pH 8.0) recipe
A chelator that binds calcium far more strongly than magnesium. Like EDTA, it dissolves near pH 8.
🧮 Volume calculator
| Component | Amount | Final concentration (1X) |
|---|---|---|
| EGTA (free acid) | 19.02 g | 0.5 M |
| 10 M NaOH | as needed | to pH 8.0 |
| Water (distilled) | to final volume |
Steps
- Add EGTA to about 70% of the final volume of water and stir (it will not dissolve yet).
- Add 10 M NaOH gradually; it dissolves as the pH reaches 8.0.
- Bring to the final volume with water.
- Autoclave (121 °C, 20 min) and store at room temperature.
FAQ
Why EGTA rather than EDTA?
Use EGTA when you want to remove Ca²⁺ but keep Mg²⁺ (e.g. blocking calcium-dependent processes).
This is a widely used standard composition. Amounts depend on the hydrate form and purity of your reagents — check the formula weight (FW) on the bottle and follow your institution's safety rules and the manufacturers' instructions.