Birth Date: July 12, 1913
Date of Death: October 12, 2009 (age 96)
Place of Birth: New York, United States
Place of Death: Philadelphia, Pennsylvania, United States
Nationality: American
Occupation/Field of Study An American Biochemist, a pioneer of the technique of nuclear magnetic resonance.


KEYWORDS: Mildred Cohn, Biochemistry, MRI, Molecular Biology.


Mildred Cohn was an American biochemist the most known as a pioneer in applying new technologies to measure organic reactions. Despite that she was born into a family with the Jewish background and her parents were immigrants, she conquered the prejudice of the time. She was an outstanding and driven student given the fact that she has graduated from high school when she was fourteen years old.³ Thus not only an incredibly talented young woman, but as well a persistent student, she pursued her goals and built an outstanding career in biochemistry. As women in a lab were recognized as distraction in those times, she didn’t have it easy and had a load to carry. Additionally, throughout her career she faced many obstacles and discrimination due to her Jewish origin. No matter the outer opinion and judgements she achieved more than many men and gained remarkable recognition in science.

Cohns’ most noticeable research work included development of a magnetic resonance imaging or an MRI. She used magnetic forces to examine the atomic nucleus in order to study the shapes of molecules and identify compounds.⁴ Her research activities focused on the utilization of isotopes and she became an admirable authority  in this field of research. She had the best mentors she could have at the time, when surrounded with the greatest researchers, most of them awarded with the Nobel Prizes for the achievements and knowledge they have had and passed to the further generations. As a person she was family oriented and had followed the principle of social justice. She had three children and for the children to have a working mother was quite unusual at the time.² (p. 82) She was married to the theoretical physicist Henry Primakoff who was an immigrant from Russia. He was very supportive in a way that her career had a significant value, she was treated as an intellectual companion and overall they were absolutely close to each other. Mildred Cohn is regarded as an headstrong, ‘prejudice fighting’ woman scientist who managed to work with several great scientists and the Nobel Prize receivers from different areas and had, a great husband who she called ‘cerebral and very European in the regard of housework’³ (p.82) and happy children. Her students confirmed that she was a warm person, thus demanding teacher and mentor.

During her studies she was strong and focused on her goals, as she did not listen to anybody telling her that she would not be able to become a scientist because she is a woman, or even Jewish woman. Unusual for the times she lived in, she pursued many outstanding goals on her academic and scientific path, innovated an important medical technology which today we know as a magnetic resonance imaging or an MRI and together with others developing techniques and instruments that helped to study the protein behaviour in the body.



Mildred Cohn was born in New York City on the 12th of July, 1913 to Isidore and Bertha (Klein) Cohn, Jewish – Russian immigrant parents. The fact that her father was a rabbi – Jewish teacher had a huge effect in Mildred’s life. Not only was she a woman, she was a Jewish woman who was interested in chemistry and science, which occurred to be unimaginable at the time. Very keen and motivated Mildred Cohn had a very good chemistry teacher in high school, which seemed to have a big role and appealed her to chemistry. She found physics even more enticing, when studying at Hunter College, but the school did not yet provide it as a primary subject, so Cohn graduated in chemistry with physics as her secondary study.² (p.81)

Due to anti-Semitic manners of the time, she could not apply for graduate school, thus spent her savings and attend Columbia University where, again, she was mistreated because teaching assistantships were available only for male students.² (p81) Between 1934 and 1937 Cohn was a student from Harold Urey, who in 1934 won the Nobel Prize in Chemistry. Urey tried to discourage her, saying that he did not mentor his students much and expected them to teach themselves, which she did not take as a good argumentation, thus persisted and he finally admitted her to join the research group.³ To earn the money for the university tuition she lived at home and did babysitting jobs and as long as she finished her master’s degree another job opportunity showed up at the National Advisory Committee of Aeronautics at Langley Field in Virginia.¹ (p.92) There she was, as the only woman among seventy men, involved in the designing project about an aircraft diesel engine. No matter her job future prospects, she had gained valuable experience in applied research field and most importantly saved enough money to return to Columbia University and insisted in getting a mentorship from Professor Isidor Rabi. Nobel winner in physics (1944) for devising a method for observing atomic spectra was a suitable mentor and Cohn started to study isotope separation. At first she failed, due to equipment problems, to separate ¹²C and ¹³C, thus continued working on the exchange of isotopic water (H² ¹⁸O) with organic compounds such as acetone.¹ (p.92) She was the smallest person in the laboratory and when Urey wanted to determine the volume of water in the body she was asked to be the experimental subject, but this idea was not very thrilling for Cohn.¹

Surprisingly, Cohn had been a PhD research student for twenty years before she went after a professorship. During her research and teaching times she worked with another Nobel laureate (1955), biochemist Vincent du Vigneaud. She moved from Columbia to du Vigneaud’s lab in Washington and in the late 1930s together with him to the Cornell University in Ithaca, New York.³ In his laboratory she utilized isotopic tracers to follow sulfur amino acid metabolism and also studied transmethylation. From her point of view working there was much of a difference as she had imagined, due to the fact that individual researchers would do only a limited part of a project, with du Vigneaud coordinating all the parts.¹ (p.93) Anyways, she had spent nine years working for/with him and made many experiments which resulted in building electrophoretic apparatus used to separate proteins. Another important innovation was a mass spectrometer which she produced to separate and measure compounds on the basis of their mass. In her work with du Vigneaud, this was used to follow the metabolism of components labeled with stable isotopes.¹ (p.94) In the times working and living in Washington she met Henry Primakoff who was a scientific peer of her and he became her supportive husband and soulmate. Surprisingly, Cohn could have not been employed by the same university because of the anti nepotism rules at the times. The fact that Mildred was a Jewish woman scientist who had husband from the same university, it is the prove for the challenges she was facing. For twenty-one years she did not have a faculty position which had financial effect on one hand, but she could focus only on the research projects and put her soul and heart into it on other. Her first two children were born during the World War Ⅱ and staying in the research field was good because it was easier to stay home when the children were not healthy. Nonetheless, the family had a home helper to take care of the housework and children, thus Cohn was able to stick to her work in the laboratory. Nevertheless, she had to stand a tremendous social pressure against that she had been working as a mother. Their children were all highly involved in studies (they all obtained PhD) and the oldest daughter Nina was interested in psychology, and wrote an essay about the effects on children of having a working or nonworking mother.² (p.83) In the interview with Hargittai Mildred Cohn revealed the truth:

”I got a lot of criticism from relatives. /…/ After I had my first child, my mother-in-law carried on a campaign to get me to quit working, but she didn’t succeed. One of the reasons my oldest daughter reacted as she did was that when she was in second grade, she was 7 years old, she joined the Brownies and when the woman who ran it found out that I worked she told my child that I was a bad mother. ”² (p.83)


In 1946 Cohn joined the Cori laboratory in St. Louis to work with Carl and Gerty Cori. She was one of the first students who used nuclear magnetic resonance and electron paramagnetic resonance to study enzymatic reactions.¹ (p.95) They encouraged her to work independently and she was determined to make experiments on her own to enhance determining the structure of ATP (adenosine triphosphate). Few years after she decided to work on oxidative phosphorylation and join Paul Boyer at Harvard. At this point she decided to deal with the more controllable problem which was the mechanism of kinases; enzymes that utilize ATP to phosphorylate protein substrates.¹ (p.96) Later, in 1955, she spent one year working in the elucidation of the structure of metal-ATP-enzyme complexes in the laboratory of Hans Krebs at Oxford. Few years later Cohn’s husband got the place as Donner Professor of Physics at the University of Pennsylvania and she entered the Johnson Foundation under the direction of Britton Chance who was an outstanding person “with a love of the sea that manifested itself in a love of sailing and the invention of an automatic steering device for ships.”¹ (p.97) He was very abetting when Cohn wanted to explore the structural changes in ATP and ADP. When working in the Johnson Laboratory, she had a great chance for establishing the experiments and the evidence of the nature of the complexes between the nucleotides and the metal ions which she better described in the article published in the Journal of Biological Chemistry. Many of her papers and articles were and still are the quotation classic in the field of chemistry and biology. In 1965 Cohn became a full professor at the University of Pennsylvania School of Medicine and she was awarded a Career Investigatorship of the American Heart Association.¹ (p.98)

It was a very big shock for her when her husband died in 1983, because they were very close. The same year when Cohn was awarded the National Medal of Science (1982), she retired but remained active at the university until just a few months before she passed away in 2009. The National Women’s Hall of Fame inaugurated her the day after her death and her inheritance lived on with her students, all the achievements and innovations she had made had a tremendous effect on positioning women in science, specifically chemistry and biology.



All her career, Mildred Cohn was surrounded by great assembly of scientists, many of them the Nobel Prize winners. Certainly she was affected by their intellectual work, he enthusiasm and cerebral spirit.

As described in one of her recollections, in the spring of 1938, she was present at an encounter between two giants of physics (Rudolf Schoenheimer and David Rittenberg), which she portrayed as being of historical dimensions.¹

She was the first woman elected to the editorial board of The Journal of Biological Chemistry and the first to become president of the American Society for Biochemistry and Molecular Biology.



”The first thing I would suggest is, marry the right man. That’s the most important thing. You have to have a husband who is fully supportive. That he does more than paying lip service to equality. My husband was really a feminist. He liked women and respected them. My second advice is whatever decision they make they shouldn’t feel guilty.”

Hargittai Magdolna, Candid Science III


”The piece of advice for women scientists. They should stress the scientist more than the woman. /…/ I read about a famous physicist who was considering going to Israel, but he hesitated. His wife persuaded him to seek Einstein’s advice. So he went to Einstein and Einstein sad to him, ”I’m a scientist first and a Jew second.” The same thing is for women. They should be scientists first if that’s what they are interested in, and a woman scientist second.”

Hargittai Magdolna, Women Scientists: Reflektions, Challenges, and Breaking Boundaries (p.84)



”Mildred was a tiny woman, she was very small, but when she walked into the room it was very clear that she filled the place up and everybody treated her with the utmost respect. /…/ She was really renowned in the field; I was thrilled to find her because of number of reasons; she turned out to be a fabulous mentor, she was an incredibly warm person but she was also very demanding, scientifically demanding.”

Eileen Jaffe, Midlred’s graduate student; video (URL:


”Here is an example of a woman who had tremendous ability but who was in secondary positions in academia practically until the time when she was elected to the National Academy of Sciences. Mildred continued to make important contributions to enzymology and oxygen-18 measurements that influenced my research over the years.”

Paul Boyer, Interview about Mildred Cohn in 1999.² (p.80)



1963: The American Chemical Society’s Garvan-Olin Medal;

1968: She was elected a Fellow of the American Academy of Arts and Sciences;

1975: The Franklin Institute’s Elliott Cresson Medal;

1979: The International Organization of Women Biochemists Award

1983: She was presented with the The National Medal of Science;

1986: Columbia University’s Chandler Medal

2009: She was inducted into the National Women’s Hall of Fame in New York.



Cohn, Mildred; Hughes, T. R. (1960). “Phosphorus magnetic resonance spectra of adenosine diphosphate and triphosphate. I. Effect of PH”. The Journal of Biological Chemistry. 235: 3250–3.

Cohn, Mildred; Hughes, T. R. (1962). “Nuclear magnetic resonance spectra of adenosine di- and triphosphate. II. Effect of complexing with divalent metal ions”. The Journal of Biological Chemistry. 237: 176–81.

Cohn, Mildred (1953). “A study of oxidative phosphorylation with 0-18 labeled inorganic phosphate”. The Journal of Biological Chemistry. 201: 735–50.



  1. Exton H., John, (2013), Mildred Cohn – Against All Odds, Crucible of Science: The Story of the Cori Laboratory, New York, Oxford University Press.
  2. Hargittai, Magdolna, (2015), Women Scientists: Reflection, Challenges, and Breaking Boundaries, New York, Oxford University Press.
  3. Chemical Heritage Foundation, Mildred Cohn, <> (last accessed 31 Oct. 2017)
  4. Martin, Douglas, (11 Nov. 2009), The New York Times, Mildred Cohn, Biochemist, Is Dead at 96, <> (last accessed 27 Oct. 2017)
  5. Indivero M., Victoria, (2010), A First Lady of Chemistry, Chemical Heritage Foundation. <> (last accessed 30 Oct. 2017).


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