Dr Mildred Cohn: Pioneering Biochemist Who Transformed Understanding of Metabolism and Human Physiology

Dr Mildred Cohn (1913–2009) was an American biochemist whose innovative application of nuclear magnetic resonance (NMR) revolutionised the study of metabolism and human physiology. Her work provided unprecedented insight into how biochemical reactions occur in living systems, profoundly influencing physiology, enzymology, and modern biomedical research.

Early Life and Education

Mildred Cohn was born on 12 July 1913 in New York City, United States. She showed early aptitude for science but faced significant barriers as a woman pursuing a scientific career in the early 20th century (National Academy of Sciences, 2011).

She earned her undergraduate degree in chemistry from Hunter College in 1934. Denied admission to graduate programmes at several universities because of her gender, Cohn began her research career as a laboratory assistant before eventually enrolling at Columbia University, where she completed her PhD in physical chemistry in 1938 (Encyclopaedia Britannica, 2024).

Early Research and Metabolic Studies

During the Second World War, Cohn worked on isotope research related to synthetic rubber production, developing expertise in isotopic tracers — techniques that would later prove critical in metabolic research (National Academy of Sciences, 2011).

After the war, she joined the Washington University School of Medicine in St Louis, where she began applying isotopic labelling to investigate enzyme-catalysed reactions. Her work helped clarify how enzymes facilitate metabolic pathways by tracking atoms through complex biochemical processes (Cohn, 1949).

Transforming Physiology with NMR

Dr Cohn’s most influential contributions came from her pioneering use of nuclear magnetic resonance spectroscopy in biological systems. At a time when NMR was primarily a tool of physics, Cohn recognised its potential to study biochemical reactions in real time.

In the 1960s and 1970s, she used NMR to elucidate the role of adenosine triphosphate (ATP) in energy transfer, demonstrating how metal ions such as magnesium interact with ATP during metabolic reactions. This work fundamentally advanced understanding of cellular energy metabolism, a cornerstone of human physiology (Cohn & Hughes, 1962).

Her research allowed scientists to observe metabolic processes non-invasively, paving the way for later clinical applications such as magnetic resonance imaging (MRI) and magnetic resonance spectroscopy in medicine (Encyclopaedia Britannica, 2024).

Academic Leadership and Mentorship

In 1960, Cohn joined the University of Pennsylvania, where she became a professor of biochemistry and biophysics. She remained scientifically active well into her later years, continuing to publish influential research and mentor generations of scientists (University of Pennsylvania, 2015).

Despite persistent gender discrimination early in her career, Cohn became a respected leader in science. In 1978, she was elected to the United States National Academy of Sciences, one of the highest honours for a scientist in the United States (National Academy of Sciences, 2011).

Legacy

Dr Mildred Cohn died on 12 October 2009 at the age of 96. Her legacy lies in transforming how scientists understand metabolism at the molecular level and linking physical chemistry with human physiology.

By introducing powerful physical techniques into biology, Cohn reshaped biomedical research and enabled deeper insight into diseases involving metabolic dysfunction. Her work remains foundational to modern biochemistry, physiology, and medical imaging.

References

• Cohn, M. (1949). Isotopic studies of enzyme-catalysed reactions. Journal of Biological Chemistry, 180, 771–781.

• Cohn, M., & Hughes, T. R. (1962). Nuclear magnetic resonance studies of metal–ATP complexes. Journal of Biological Chemistry, 237, 176–181.

• Encyclopaedia Britannica. (2024). Mildred Cohn. https://www.britannica.com

• National Academy of Sciences. (2011). Biographical Memoir of Mildred Cohn. https://www.nasonline.org

• University of Pennsylvania. (2015). Mildred Cohn and the development of biological NMR. https://www.med.upenn.edu