10X PCR buffer (for Taq) recipe
The classic 10X reaction buffer for Taq DNA polymerase: 100 mM Tris-HCl pH 8.3, 500 mM KCl, 15 mM MgCl₂.
🧮 Volume calculator
| Component | Amount | Final concentration (1X) |
|---|---|---|
| 1 M Tris-HCl (pH 8.3) | 1 mL | 100 mM (10X) |
| 1 M KCl | 5 mL | 500 mM (10X) |
| 1 M MgCl₂ | 150 µL | 15 mM (10X) |
| Nuclease-free water | to final volume |
Steps
- Combine everything with nuclease-free water.
- Filter, aliquot and store at −20 °C.
- Add at 1/10 of the reaction volume (1.5 mM MgCl₂ final).
Good to know
- Making it Mg-free and adding MgCl₂ separately (1.5–3 mM) makes optimisation easier.
- Older recipes also include 0.01% gelatin.
FAQ
Does it work for other polymerases?
No — high-fidelity enzymes (Pfu, Q5-type, etc.) need their own buffers.
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.