We could safely say that DNA was not discovered by one man. Though it was first discovered by Friedrich Miescher in 1869, while examining puss in the surgical bandages, he was not aware of the microscopic substance. He named it “Nuclein” as he had observed it in the nuclei of the cells. Then in 1928, Fredrick Griffith observed that this substance might hold genetic information.
It was William Astbury who took the study further in 1937 by producing first X-ray diffraction revealing that the DNA had a regular structure. In 1943 the Avery-Macleod-McCarty experiment identified DNA as the transforming principle. Another experiment by Alfred Hershey and Martha Chase confirmed that DNA played a role in heredity.