hree major steps in a PcR: 20 to 40 cycles
Denaturation at around 94-95°C .
dsDNA melts open to ssDNA, all enzymatic reactions stop .Annealing at around 30-60 C .
Hydrogen bonds are constantly formed and broken between the single stranded primer and the single stranded template If the primers exactly fit the template, the hydrogen bonds are so strong that the primer stays attached .
Extension at around 72°C .DNA polymerase adds dNTP's from 5' to 3', reading the template from 3' to 5' side, bases are added complementary to the template