Describe the steps of PCR technique.

Explanation

There are three steps of PCR technique, viz. heat denatura- tion, annealing and polymerization. These steps are described in the following lines :

(1) Heat denaturation : In heat denaturation, the DNA is heated at `91^(@)C`. Owing to heating, the hydrogen bonds in the DNA molecule are broken. This results in the formation of ss DNA.
(2) Annealing: During annealing or DNA melting ss DNA is paired with primers. The primers are designed as per the requirements. This step is carried out at `55^(@)C`.
(3) Polymerization: In this step, the temperature is raised to `72^(@)C`. The taq polymerase is added. This helps in adding dNTPs behind the primer on the ss DNA.