Erwin Chargaff was an Austro-Hungarian biochemist who immigrated to the United States during the Nazi era and was a professor of biochemistry at Columbia University medical school. Erwin Chargaff was born in Austria on August 11, 1905. He graduated from high school at the Maximiliangynasium in Vienna and proceeded to the University of Vienna. In 1928 he obtained a doctoral degree in chemistry after having written a thesis under the supervision of Fritz Feigl at Spath's Institute. Chargaff was able to publish several scientific papers which primarily dealt with studies concerning nucleic acids like DNA. Chargaff discovered two rules that helped lead to the discovery of the double helix structure of DNA. He used chromatographic techniques in his studies, and his interest in DNA started after the identification of this molecule as the main basis of heredity. Chargaff discovered two rules that helped lead to the discovery of the double helix structure of DNA. In 1974, he received the National Medal Of Science. Chargaff died in 2002 at age ninety-six at his home in Central Park West in New York City