>>7626395during the first pcrs, researchers used "normal" (not completely sure, but probably from e.coli or yeast) polymerases.
they had to heat it up to the primer-specific temp, the primers annealed, and then they added the heat-unstable polymerase. if u ever worked in a lab, u know that adding enzymes after every cycle is extremely time-consuming and annoying.
so pcr worked before, but the discovery of taq-polymerase made it much easier and quicker. probably more cost-efficient,too
