Class 12 NEET Biology Biotechnology Principles and Processes

The first step in the polymerase chain reaction is denaturation during which strands of dsDNA separate. This requires temperature around 94°C.
This is followed by annealing in which primers anneal to 3' end of template DNA strand.
Annealing is followed by extension in which Taq polymerase adds nucleotides to 3'OH end of primers.