Identify and explain steps ‘A’, ‘B’ and ‘C’ in the PCR diagram given below.

A- Denaturation, B- Annealing, C- extension

Denaturation- in this step double stranded DNA is denatured at high temperature of 94⁰C for 15 seconds.

DNA strands separates, and act as template.

Annealing-Primers are added to anneal. This is done at 45⁰ C using Mg²⁺ ions.

Extension- Taq polymerase is used to extend the primer by adding nucleotides at a temperature of 72⁰C.