Mildred Cohn

American biochemist

• Born: July 12, 1913; New York, New York
• Died: October 12, 2009; Philadelphia, Pennsylvania

Cohn spent her scientific career in the study of molecules and their roles in metabolic reactions. Her research into magnetic forces played a significant role in the development of medical instrumentation and applications in new techniques, such as magnetic resonance imaging (MRI).

Primary fields: Biology; chemistry

Specialties: Biochemistry; biophysics

Early Life

Mildred Cohn (kohn) was born in New York City in 1913, the second child of Russian Jewish immigrants Isidore Cohn and Bertha Klein. Cohn excelled in school and skipped several grades. She first developed an interest in science and mathematics while attending public high school in New York City, graduating at the age of fourteen. As Cohn later described her schooling, she considered herself fortunate that her school provided two years for study of the science while most high schools of the period offered only one year of chemistry. Cohn’s interest in chemistry was further piqued by her best friend’s father, a beauty salon owner who manufactured some of his own cosmetics.

At the age of fourteen, Cohn enrolled at Hunter College in New York, majoring in chemistry. Her interests had veered to the study of physics, but the college did not offer a program in that area because the prevailing perspective in society at the time excluded women from career paths as scientists. Cohn had to be satisfied with a minor in physics. Encouragement from her teachers was mixed. The chairman of the chemistry program, Charles Moore, told Cohn it would not be ladylike for a woman to become a chemist and that the purpose of the chemistry program was to train women to become chemistry teachers rather than actual chemists.

Cohn was awarded a bachelor’s degree cum laude in 1931 and prepared to further her education in a graduate program at Columbia University. She was unable to obtain scholarship money at Columbia or even to serve as a paid teaching assistant because such positions were open only to men. Cohn was forced to use her own savings to pay for her education, earning money by working as a babysitter. She spent a year studying with Harold Urey, who would eventually receive the Nobel Prize in Chemistry in 1934 for his work leading to the discovery of the heavy isotope deuterium. Cohn received her master’s degree in chemistry in 1932. However, her inability to obtain scholarship money forced her to leave school, temporarily interrupting her education.

Life’s Work

In 1932, Cohn entered the workforce with a job at the National Advisory Committee for Aeronautics, forerunner of the National Aeronautics and Space Administration (NASA), at Langley Field, Virginia. There she became involved with computational work on a project dealing with ignition systems in airplane engines. In 1934, Cohn returned to Columbia University to continue work toward a doctorate.

Working again under the direction of Urey, Cohn began her research with a project involving the separation of carbon isotopes. Urey also found a source of financial aid for Cohn through a work-study program, the National Youth Act, and even provided a loan from his Nobel award to supplement her salary. Unfortunately, the instrument necessary for carrying out the work, a special type of mass spectrometer, was not yet available. Cohn’s experiments continued to produce few useful results, and after a year she decided to pursue a different project: studying isotopes of oxygen. She did, however, learn the glass-blowing skills she needed to create glass vacuums in which to conduct vacuum system experiments. In 1937, Cohn received her PhD in physical chemistry.

Jobs remained scarce through the late 1930s, and even where industrial jobs did exist, few employers would hire either a woman or a Jew. Urey was able to arrange for a postdoctoral position for Cohn at George Washington University Medical School, working with future Nobel laureate Vincent du Vigneaud. In 1938, Cohn accompanied du Vigneaud to the medical school at Cornell University. That year Cohn married physicist Henry Primakoff, whom she had met at Columbia while a graduate student. They had three children.

Cohn worked with du Vigneaud for nine years. During that time, she pioneered the effort to use isotopic labels to track the metabolism of compounds that contained sulfur. In 1946, Cohn moved with her husband to Washington University in St. Louis, where she began working with Carl and Gerty Cori, a husband-and-wife research team who would be awarded the Nobel Prize in Physiology or Medicine the following year for discovering the course of the catalytic conversion of glycogen, a molecule that animals and fungi use for long-term energy storage. The research program carried out by the Coris involved the study of sugar metabolism in an area that Cohn independently continued. Applying new procedures such as X-ray diffraction and developing instrumentation utilizing nuclear magnetic resonance, Cohn provided an understanding of structural changes to molecules during metabolic reactions.

In 1958, Cohn was promoted to associate professor of biochemistry. In 1960, she moved to the University of Pennsylvania (UPenn), becoming a full professor in 1961. In 1964, she was the first woman chosen to be an American Heart Association career investigator. Cohn retired from this position after fourteen years and retired from UPenn in 1982, after having taught as the Benjamin Rush Professor Emerita of Biochemistry and Biophysics. Cohn died of respiratory failure at the age of ninety-six on October 12, 2009.

Impact

Cohn performed important work applying instrumentation, some of which she designed herself, to the understanding of metabolic processes. For example, her use of nuclear magnetic resonance enabled her to provide an improved understanding of the mechanisms by which enzymes catalyze metabolic reactions. During her professional career, Cohn published more than 160 scientific papers, and she was elected to the National Academy of Sciences, the American Academy of Arts and Sciences, and the American Philosophical Society. She was also awarded nine honorary doctorates.

Cohn accomplished her work despite having to overcome a great deal of gender and ethnic discrimination during much of her early professional career. Cohn broke the gender barrier several times during her career, becoming the first woman named to the Journal of Biological Chemistry’s editorial board as well as the first woman president of the American Society for Biochemistry and Molecular Biology. Cohn’s career milestones and the respect that she earned for her achievements helped open doors for the next generation of women scientists.

Bibliography

Ainsworth, Susan J. “Mildred Cohn.” Chemical & Engineering News 87.50 (14 Dec. 2009): 41. Print. Presents Cohn’s obituary.

Hargittai, Istvan. Candid Science III: More Conversations with Famous Chemists. London: Imperial Coll. P, 2003. Print. One of a series of books by the author in which scientists are interviewed. Cohn describes her early life and her reasons for developing an interest in science.

Kresge, Nicole, Robert D. Simoni, and Robert L. Hill. “Succeeding in Science despite the Odds; Studying Metabolism with NMR by Mildred Cohn.” Journal of Biological Chemistry. 284 (2009): e12–e13. Print. Presents biographical information as well as details about Cohn’s work with nuclear magnetic resonance and her study of oxidative phosphorylation.

Wasserman, Elga. The Door in the Dream: Conversations with Eminent Women in Science. Washington, DC: Joseph Henry P, 2000. Print. Presents an interview with women elected to the National Academy of Sciences. Questions address their challenges, including those faced by Cohn, as the women pursued professional careers.