Scientists then apply the polymerase chain reaction or PCR, which uses artificial DNA strands called universal primers.

接着科学家们应用聚合酶链式反应，简称 PCR，使用一种被称为通用引物的人工合成 DNA 链。

Pluck out his DNA and it could be copied millions of times using a technique called the polymerase chain reaction (pcr).

取出他的遗传物质，利用聚合酶链反应技术可以复制数百万次。