•denaturation (96°
c.: heat the reaction strongly to separate, or denature, the dna strands. this provides single-stranded template for the next step. •annealing (55 - 65°
c.: cool the reaction so the primers can bind to their complementary sequences on the single-stranded template dn
a. •extension (72°
c.: raise the reaction temperatures so taq polymerase extends the primers, synthesizing new strands of dna