PCR machines have become common laboratory instruments. Generally, a PCR machine that can only run a specific annealing temperature for one PCR amplification is called a common PCR machine. A PCR machine that can set a series of different annealing temperature conditions for one-time PCR amplification is called a gradient PCR machine.

For gradient PCR machine, temperature control indicators mainly refer to temperature accuracy, uniformity, and heating and cooling speed.

1. Temperature accuracy

It refers to the consistency between the sample well temperature and the set temperature, which is directly related to the success or failure of the experiment. Since PCR is a geometric amplification process, whether it is denaturation, annealing or extension, temperature control needs to be accurately controlled. For annealing temperature, temperature control is particularly important.

2. Temperature uniformity

It refers to the temperature difference between sample wells, which is related to the consistency of reaction results in different sample wells. With the same sample, the same PCR reaction procedure, the final results are very different, which may be due to uneven temperatures at different locations. At the same time, the position edge effect has a very obvious impact on the repeatability of PCR experiments.

3. Heating and cooling rate

The faster heating and cooling rate of the PCR system can shorten the reaction time, shorten the possible non-specific binding and reaction time, and improve the specificity of the PCR reaction.