Polymerase Chain Reaction (PCR [local]), a clever enough idea [local] to win a Nobel Prize.

Go to the following site and view the appropriate animation. Pay attention to the rate at which the DNA sequence between the two primers is amplified by each thermal cycle. This is the power of PCR. It is now possible to start with a single DNA molecule and rapidly prepare chemical amounts of this 'stuff of life'. This has truly revolutionized what is possible in the laboratory.