How PCR works
Maverick scientist Kary Mullis invented this powerful new technique in 1986. PCR uses the natural ability of DNA to copy itself, using a builder enzyme. During PCR, the enzyme copies a section of DNA in the sample millions of times using the bases A, C, G and T as the raw materials, and short strands of DNA called primers to start the process. Scientists can obtain plenty of DNA from a few cells in just an hour or so.