Physical Studies of the Molecular Structure of Deoxyribose Nucleic Acid and Nucleoprotein

Abstract

It may be useful at this time to consider how much we know about DNA structure and how much we do not know. It is about six years since clear X-ray diffraction photographs of DNA were first obtained, and three years since Watson and Crick (1953) built their molecular model of DNA (then described by Watson at the Symposium here), and proposed a hypothesis to explain how DNA molecules could be replicated in vivo. We have now much data to show that their general idea for the structure is correct, but evidence bearing on the biological hypothesis is somewhat conflicting. It seems necessary to stress that correctness of the structure does not imply correctness of the biological hypothesis. In the next decade we can expect that an increasing number of molecular structures will appear and become part of biology, and, as the derivation of such structures is not easily...