In 1985, Kary Mullis was driving late at night through the flowering buckeye to the ancient California redwood forest, cogitating upon new ways to sequence DNA. Instead he came upon a way to double the number of specific DNA modules, and to repeat the process essentially indefinitely. 1 He thought of using two oligonucleotide sequences, oppositely oriented, and a DNA polymerase enzyme, to double the number of DNA targets. Each product would thene...