Chargaff, Erwin (1905-2002)

Czech-born US biochemist, best known for his work on the base composition of deoxyribonucleic acid (DNA). In 1950 he demonstrated a simple mathematical relationship between the proportions of nitrogenous bases in DNA. He worked in many fields of biochemistry, publishing on diverse topics such as how the body metabolizes fats and how blood coagulates.

His most influential work was his calculations of the chemical composition of DNA. In 1950, Chargaff published a simple mathematical relationship between the proportions of nitrogenous bases (molecules that connect the two strands of the DNA molecule like the rungs of a twisted ladder). He showed that the number of adenine molecules equals the number of thymidine molecules, and that the number of guanine molecules equals the number of cytosine molecules.

Chargaff was born in Czernowitz, which was then part of Austria but is now part of the Ukraine. He studied in Vienna and at Yale University in the USA. When Watson and Crick published their seminal work on DNA structure a few years later 1953, they claimed to have been unaware of Chargaff's work.

Although Chargaff made an important contribution to the early study of genetics, he went on to become a stern critic of molecular biology stating that ‘by its claim to be able to explain everything, it actually impedes the flow of scientific explanation’.