Erwin Chargaff was an Austro-Hungarian biochemist that immigrated to the United States during the Nazi era and was a professor of biochemistry at Columbia University medical school. Through careful experimentation, Chargaff discovered two rules that helped lead to the discovery of the double helix structure of DNA.
The first rule was that in double-stranded DNA the number of guanine units is equal to the number of cytosine units, and the number of adenine units is equal to the number of thymine units. This hinted at the base pair makeup of DNA. It has also been found that the melting temperature of DNA (temperature at which 50% of double strands separate) correlates with GC content, in part due to increased hydrogen bonding in G-C pairs.
The second rule was that the relative amounts of guanine, cytosine, adenine and thymine bases vary from one species to another. This hinted that DNA rather than protein could be the genetic material.
Erwin Chargaff Married Vera Broido on 17 Sep 1929 in Manhattan, New York, New York, United States
Father's Name: Herman Chargaff
Mother's Name: Rosa Silberstein
Spouse's Birth Year: 1907 (Age 22) Birthplace: Russia
Spouse's Father's Name: Leo Mother's Name: Tomasi F. Ratner 
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