One cycle of Polymerase Chain Reaction involves three basic steps:
1. Denaturation
2. Annealing
3. Polymerization
1. Denaturation:The desired DNA is heated to a high temperature of about 91°C and forms a single-stranded DNA. It results in the separation of the two strands of DNA, each of which would function as a template for the synthesis of a new molecule of DNA.
2. Annealing:It is the process in which the two primers (oligonucleotides) hybridize to each of the strands of DNA. It requires a temperature of 55°C.
3. Polymerization:In this step, the Taq polymerase carries out the synthesis of the DNA region between the two primers by using deoxyribonucleotides (dNTPs) and Mg2+. The optimum temperature for this polymerization reaction is 72°C.
