Science Fundamentals: Polymerase Chain Reaction

Science Fundamentals is a series on foundational concepts in science. My goal is to give you the tools to critically think and discuss scientific concepts in everyday language and without the grind of actually getting a Ph.D.

In a variety of science fields, you start with a very small amount of DNA, and you need to study it or do something with it. However, that small amount isn’t going to be enough. You could go through the process of extracting more DNA, but sometimes this is impossible (Wooly Mammoth’s DNA is rather hard to find these days). So how do you make more? It isn’t like you can stick DNA in the office copier down the hall. Polymerase Chain Reaction, or PCR, makes millions of copies of DNA from a single piece of DNA. It was invented in 1983 by Kary Mullís and Michael Smith, and they eventually received the Nobel prize for this in 1993. Since then, PCR has become essential to modern science.

Procedure

PCR is a scientific technique, and so it has a defined protocol, or recipe. The components, or ingredients are

Template DNA, which is the DNA that you want to make copies

dNTPs (which stands for the fancy name: deoxygenated nucleotides triphosphate) which are the building blocks of DNA. I called them nucleic acids in the Science Fundamentals: DNA, but the names mean the same thing.