PCR Master Mix Calculator
Scale a PCR master mix to any number of reactions. Set your per-reaction volumes, the reaction count and an overage for pipetting loss to get the total of each reagent.
| Component | Per reaction (µL) | Total (µL) |
|---|---|---|
| 10X reaction buffer | 27.5 µL | |
| dNTP mix (10 mM) | 5.5 µL | |
| Forward primer (10 µM) | 5.5 µL | |
| Reverse primer (10 µM) | 5.5 µL | |
| Taq polymerase | 1.38 µL |
Aliquot 4.13 µL of master mix per tube, then add template.
How it works
A PCR master mix bundles every reagent shared across your reactions — buffer, dNTPs, primers and polymerase — into one tube, so you pipette it once and aliquot equal amounts. This calculator multiplies each per-reaction volume by the number of reactions, plus an overage percentage to cover the small losses from pipetting.
A typical overage is 5–10%: preparing mix for a few extra reactions means the last tube still gets a full, accurate volume. Template DNA is added to each tube separately (not in the master mix), so the per-tube master mix volume shown is what you dispense before adding your sample.
Examples
- For 10 reactions at 10% overage, each reagent is scaled ×11.
- Template is added per tube, not to the shared master mix.
- Overage covers pipetting loss so the last tube is still full.
Frequently asked questions
- What is a PCR master mix?
- A single premixed tube of all reagents common to your reactions, aliquoted equally so every tube is identical and you pipette fewer times.
- Why add overage?
- Pipetting loses a little volume each transfer. Preparing 5–10% extra ensures the final reactions still receive a full, accurate amount.
- Is template in the master mix?
- No — template DNA differs per sample, so it is added to each tube separately after dispensing the shared master mix.
- Can I change the volumes?
- Yes. Edit any per-reaction volume in the table to match your protocol; the totals update automatically.