What this calculator does
PCR annealing temperature (Ta) works out optimal PCR annealing temperature from primer and product melting temperatures. Enter your own figures above and the answer updates as you type: nothing is fixed in the code, so the result reflects exactly the numbers you supply.
The formula this calculator evaluates is printed under the tool and explained below, so you can check the working by hand or reuse it in a spreadsheet.
The formula
The inputs explained
| Field | What to enter |
|---|---|
| Melting temp. of the least stable primer (°C) | A number, measured in °C. Starts at 58. |
| Melting temp. of the amplicon/product (°C) | A number, measured in °C. Starts at 75. |
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How the answer changes with melting temp. of the least stable primer
Every other input is held at the calculator’s starting values while melting temp. of the least stable primer varies. Select any row to load that scenario into the calculator.