Figures in DNA Discoveries

• Phoebus Levene


  discovered DNA was a polymer of nucleotides, suggested the tetranucleotide theory
• Albrecht Kossel


  discovered nitrogenous bases associated with DNA
• Erwin Chargaff


  disproved the tetranucleotide theory, created Chargaff's rules, A=T C=G
• Fred Griffith


  demonstrated transformation in bacteria, experimented with mice and strains of Streptococcus
• Oswald Avery


  discovered the "transforming principle" in DNA between DNA, RNA, and protein, built upon the work of Griffith, DNA carried the heredity information
• Alfred Hershey


  identified DNA as the genetic material in bacteriophage
• William Ashbury


  used x-ray diffraction to study DNA structure
• Rosalind Franklin


  used x-ray diffraction data to construct the structure of DNA
• Francis Crick


  modeled the 3D structure of DNA