Watson and Crick already knew that the number of purines is always the same as pyrimidines.
The scientists that contribute to discovery of DNA and its complete structure:
• Friedrich Miescher-was the first who found DNA inside the nucleus (first it was called nuclein) while he was trying to discover the protein components of leukocytes (1869)
• Phoebus Levene- was the first who discovered three major components of a nucleotide (1919)
• Erwin Chargaff –discovered that the total amount of purines (A + G) and the total amount of pyrimidines (C + T) are nearly equal (Chargaff’s rule) (1950)
• Rosalind Franklin and Maurice Wilkins, did an important X-ray crystallography work that contributed to Watson and Crick's discovery of double-helical model for the structure of DNA.
