When they separate, the primers that you've added automatically bind through the process of hybridization, and then you turn up the temperature to the optimum for Taq polymerase and DNA synthesis starts.

当双链解旋后,加入的引物就会在杂交的步骤中自动,和解旋后的DNA结合,然后你再将温度升高至,Taq酶的最适温度,DNA就开始合成了

耶鲁公开课 - 生物医学工程探索课程节选