Erwin Chargaff was an American biochemist

Biochemist

Biochemists are scientists who are trained in biochemistry. Typical biochemists study chemical processes and chemical transformations in living organisms. The prefix of "bio" in "biochemist" can be understood as a fusion of "biological chemist."-Role:...

 who emigrated to the United States during the Nazi

Nazi Germany

Nazi Germany , also known as the Third Reich , but officially called German Reich from 1933 to 1943 and Greater German Reich from 26 June 1943 onward, is the name commonly used to refer to the state of Germany from 1933 to 1945, when it was a totalitarian dictatorship ruled by...

 era. Through careful experimentation, Chargaff discovered two rules

Chargaff's rules

Chargaff's rules state that DNA from any cell of all organisms should have a 1:1 ratio of pyrimidine and purine bases and, more specifically, that the amount of guanine is equal to cytosine and the amount of adenine is equal to thymine. This pattern is found in both strands of the DNA...

 that helped lead to the discovery of the double helix structure of DNA

DNA

Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...

. Professor emeritus of biochemistry at the Columbia University

Columbia University

Columbia University in the City of New York is a private, Ivy League university in Manhattan, New York City. Columbia is the oldest institution of higher learning in the state of New York, the fifth oldest in the United States, and one of the country's nine Colonial Colleges founded before the...

 medical school.

Chargaff had one son, Thomas, with his wife Vera Broido, whom he married in 1928. Chargaff became an American citizen in 1940.
Chargaff was born in Czernowitz on August 11, 1905, Bukowina

Bukovina

Bukovina is a historical region on the northern slopes of the northeastern Carpathian Mountains and the adjoining plains.-Name:The name Bukovina came into official use in 1775 with the region's annexation from the Principality of Moldavia to the possessions of the Habsburg Monarchy, which became...

, Austria

Austria-Hungary

Austria-Hungary , more formally known as the Kingdoms and Lands Represented in the Imperial Council and the Lands of the Holy Hungarian Crown of Saint Stephen, was a constitutional monarchic union between the crowns of the Austrian Empire and the Kingdom of Hungary in...

, which is now Chernovtsy

Chernivtsi

Chernivtsi is the administrative center of Chernivtsi Oblast in southwestern Ukraine. The city is situated on the upper course of the River Prut, a tributary of the Danube, in the northern part of the historic region of Bukovina, which is currently divided between Romania and Ukraine...

, Ukraine

Ukraine

Ukraine is a country in Eastern Europe. It has an area of 603,628 km², making it the second largest contiguous country on the European continent, after Russia...

.

From 1924 to 1928, Chargaff studied chemistry

Chemistry

Chemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds....

 in Vienna

Vienna

Vienna is the capital and largest city of the Republic of Austria and one of the nine states of Austria. Vienna is Austria's primary city, with a population of about 1.723 million , and is by far the largest city in Austria, as well as its cultural, economic, and political centre...

, receiving a doctorate

Doctor of Philosophy

Doctor of Philosophy, abbreviated as Ph.D., PhD, D.Phil., or DPhil , in English-speaking countries, is a postgraduate academic degree awarded by universities...

.