The Polymerase Chain Reaction

Co-edited by Kary Mullis, the 1993 Nobel Prize Winner for Chemistry for the invention of the polymerase chain reaction (PCR) technique, this handbook on PCR covers essential methodologies for the laboratory, as well as new techniques and enhanced applications. James D. Watson When, in late March of 1953, Francis Crick and I came to write the first Nature paper describing the double helical structure of the DNA molecule, Francis had wanted to include a lengthy discussion of the genetic implications of a molecule whose struc­ ture we had divined from a minimum of experimental data and on theoretical argu­ ments based on physical principles. But I felt that this might be tempting fate, given that we had not yet seen the detailed evidence from King's College. Nevertheless, we reached a compromise and decided to include a sentence that pointed to the biological significance of the molecule's key feature-the complementary pairing of the bases. "It has not escaped our notice," Francis wrote, "that the specific pairing that we have postulated immediately suggests a possible copying mechanism for the genetic material." By May, when we were writing the second Nature paper, I was more confident that the proposed structure was at the very least substantially correct, so that this second paper contains a discussion of molecular self-duplication using templates or molds. We pointed out that, as a consequence of base pairing, a DNA molecule has two chains that are complementary to each other. Each chain could then act ". . . as a template for the formation on itself of a new companion chain, so that eventually we shall have two pairs of chains, where we only had one before" and, moreover, " ...