a process in which a particular piece of DNA is copied many times in a laboratory (= a place where scientific tests are done) so that the DNA can be examined in detail

To obtain enough of the gene to work with, the researchers make multiple copies of it using a technique called polymerase chain reaction.

Polymerase chain reactions were performed in batches of 10 samples. 聚合酶链式反应是以10个样品为一批进行的。