PCR Master Mix Calculator

How to make a PCR master mix

1. Enter the number of reactions, the extra to allow for pipetting losses, the reaction volume and the template volume per reaction.
2. Edit the components to match your kit: each line is a name, its stock concentration and the final concentration you want.
3. The table lists the volume of each component per reaction and for the whole mix, with water to make up the volume.

Frequently asked questions

How is each volume worked out?

Volume per reaction = final concentration ÷ stock concentration × reaction volume, from C1V1 = C2V2. The master mix volume is that times the number of reactions plus the extra.

Why add extra?

Some liquid stays in the tube and the tips. 10% extra, or one extra reaction for every 10, makes sure the last tube gets its full share.

My kit is a 2× master mix. What do I enter?

Replace the lines with "Master mix 2 1" and your primers; the water line fills the rest.

Does the polymerase line use units?

Yes: enter the stock in U/µL and the final in U/µL of reaction. 0.025 U/µL is 1.25 U in a 50 µL reaction, a common amount for Taq.