On February 28, 1953, American molecular biologist James D. Watson and English biophysicist Francis Crick announced to friends that they succeeded to determine the chemical structure of DNA.
On September 4, 1906, German biophysicist and Nobel laureate Max Delbrück was born in Berlin. His best known achievement for that he won the Nobel prize was the discovy that bacteria become resistant to viruses (phages) as a result of genetic mutations.