The document summarizes the key discoveries that led to determining the double helix structure of DNA. It describes early work in isolating and studying nucleic acids. It then explains Chargaff's rules of base pairing and the experiments proving DNA is the genetic material. The document outlines Linus Pauling's incorrect triple helix model of DNA structure and describes how in 1953, Watson and Crick published their landmark paper revealing the correct double helix structure of DNA, based on evidence including Photo 51. Watson, Crick and Wilkins were later awarded the Nobel Prize for this revolutionary discovery.