1 M CaCl₂ recipe
A calcium stock for enzyme reactions, cell-adhesion buffers and making competent cells.
🧮 Volume calculator
| Component | Amount | Final concentration (1X) |
|---|---|---|
| CaCl₂·2H₂O (dihydrate) | 14.7 g | 1 M |
| Water (distilled) | to final volume |
Steps
- Dissolve in about 80% of the final volume of water.
- Bring to the final volume with water.
- Filter (0.22 µm) or autoclave. Store at room temperature.
Good to know
- Anhydrous CaCl₂ (MW 110.98) gets hot when dissolving and absorbs moisture, so weighing is inaccurate — the dihydrate is preferred.
FAQ
Why does it turn cloudy with phosphate buffer?
Calcium and phosphate form calcium-phosphate precipitate. Add calcium last, slowly and dilute.
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.