Other Ways to Use Biology for Biological Experiments

There are a number of reasons for wanting to insert foreign DNA into a cell, one of which is simply to amplify (increase) the quantity of foreign DNA by making use of a cell’s natural ability to grow and multiply. However, there is a more direct way to amplify DNA, by using of some of the cell’s DNA replication machinery in vitro. This technique is called polymerase chain reaction (PCR). To explain how it works, I will first review, at a high level, how DNA is duplicated (replicated) in a cell. (The mechanisms for this differ somewhat in prokaryotes and eukaryotes—here I will focus on prokaryotic replication).