January 2010

Mildred Cohn (1913—2009)

Mildred Cohn 300Mildred Cohn, the first female president of the American Society for Biochemistry and Molecular Biology and the first woman appointed to the Journal of Biological Chemistry editorial board, passed away on Oct. 12 at age 96. Information on Cohn’s life and pioneering work in nuclear magnetic resonance can be found in an article, titled “Mildred Cohn: Isotopic and Spectroscopic Trailblazer,” in the September 2009 issue of ASBMB Today. Below are reflections by her friends and colleagues.

Mildred Cohn was one of the great figures of 20th century biochemistry/biophysics. She influenced several generations of scientists with her brilliant use of physical methods to probe the structures and functions of proteins. She was also one of my scientific heroes. She wasn’t very tall, but if, as Robert Browning said, the best way to measure someone is by the length of the shadow that his or her mind casts, then Mildred Cohn was a giant.

Gregory A. Petsko
Gyula and Katica Tauber professor of biochemistry and chemistry
Brandeis University


Mildred didn’t have very many graduate students, and I was her last. It was 1976. Mildred distinctly told me that I could do a rotation but that she was no longer taking students. A fellowship allowed me to persist, and, one or two papers later, she officially accepted me as her student. At first, I was intimidated and couldn’t bring myself to call her “Mildred” like everyone else did. She was only slightly younger than my grandmother, and it just didn’t seem right to call someone of her generation by his or her first name!

When Mildred was elected the first female president of the American Society of Biological Chemists (now ASBMB), I don’t recall there being any great fuss about that honor in the lab. She did, however, include me in the presidential festivities at the annual meeting. While I was a student, Mildred also was honored in a fete thrown by members of the chemistry department at Penn.

But it is not the honors that stand out. Mostly, I recall the extreme pleasure of spending hours in her long, narrow and windowless office bouncing around ideas about methods and mechanisms. Mildred’s questions were piercing, and it was quite an education to learn to expect them. She was a fabulous mentor. By example, she taught both scientific integrity and generosity. Mildred also insisted that I earn first authorship on our papers by writing them myself.

Later, in my role as a student, I also got the pleasure of house-sitting for Mildred and Henry in Penn Valley. There, I came to appreciate that in her professional life she was Mildred Cohn, but in her personal life was Mildred Primakoff. In fact, when editing our papers, she would sometimes call my writing girlish, meaning not succinct, and sign her comments “MCP.” It was an era when “male chauvinist pig” was a common phrase, and Mrs. Primakoff enjoyed the irony of her initials!

When I was no longer a student, Mildred became a friend. After Henry’s death, I remember helping her hang pictures after she moved into her apartment overlooking Rittenhouse Square. Before Henry got sick, Mildred used to occasionally talk about what they would do together in their retirement. In recent years, Mildred became a theater buddy. We enjoyed countless hours in the theater, and the meals before or after were always filled with rich conversation— sometimes science, often personal.

I will miss Mildred. I will miss seeing the family photographs grow in size. I will miss hearing about the accomplishments of children and grandchildren and the arrival of great-grandchildren. I was fortunate to have become Mildred’s student when I was young and to have had her as part of my life for so many decades. I knew Mildred as a great woman, a great scientist, a great mentor and as a great friend.

Eileen K. Jaffe
Fox Chase Cancer Center


As Mildred Cohn’s first postdoctoral fellow, I was deeply saddened by her death. Mildred was a perfect mentor, inspiring by example, and was understanding and supportive of my ventures into mechanistic chemistry, tolerant of my idiosyncrasies and corrective of my errors. As an independent investigator, I long continued to rely on Mildred for sound scientific and administrative advice.

I am consoled by the fact that Mildred led a long, productive and mostly healthy life, reaching 96 years. I take great pride in my association with Mildred and by the fact that, as a medical doctor, I continued to annoy her about her smoking until she stopped at age 50, which may well have contributed to her long life. 

Albert S. Mildvan
Professor emeritus of biological chemistry and chemistry
Johns Hopkins University School of Medicine


It is a pleasure to remember Mildred Cohn as a friend and scientist. Her pioneering use of oxygen-18 for probing enzymatic reactions of phosphate compounds served as a basis for my later investigations. She cordially shared her knowledge of methodology and readily participated in discussions of mutual interest. Much of what I and my colleagues were able to accomplish was made possible by her contributions.

Paul D. Boyer
Nobel Laureate (1997)
Emeritus professor of chemistry
University of California, Los Angeles


Mildred Cohn was a brilliant, nationally and internationally respected scientist who was a wonderful role model for her fellow scientists, especially for women. In her quiet way, she broke glass ceilings and was an innovative leader in her field. She was one of a handful of scientists who attended the ASBMB 50th anniversary celebration in 1956 and the 100th anniversary celebration in 2006. At the centennial celebration, at the age of 93, she gave a priceless presentation, highlighting her career at the female scientists’ reception. The presentation captured her resilience and clarity.

Judith S. Bond
Professor and chair biochemistry and molecular biology
The Pennsylvania State University


I first met Mildred Cohn at the International Society of Magnetic Resonance meeting in Israel in 1971. I was an associate professor of physics at the Indian Institute of Technology in Kanpur. My expertise was in nuclear spin relaxation in liquids. I was fascinated by the possibility of applying this technique to investigate some biological problems. At one of the conference lunches, I serendipitously ended up sitting next to Mildred and her husband, Henry Primakoff. During the lunch, I sought Mildred’s advice about my desire to apply NMR expertise to biological problems, considering my unfamiliarity with biology. She said that it is possible to overcome the barrier with some effort and stressed the importance of collaborating with biochemists who can identify significant questions to answer. She mention)ed that she knew of physicists who used sophisticated methods to study trivial biological problems. This discussion was at the back of my mind when I wrote to her in 1972 about coming to her lab to explore my goal. She arranged a visiting scientist position for me, and, thus, a pivotal turn in my professional career occurred.

I started working in her group in December 1973. During the first six months, I was clueless as to how I could carve a niche for myself in this new field. Fortunately, Mildred knew how to communicate with and utilize the strengths of a physicist, and before long some significant results emerged.

I developed a warm personal relationship with Mildred. Her rich experience in science, and her marriage to Henry, an illustrious physicist, made Mildred a source of fascinating and entertaining anecdotes about science and scientists. She also had an excellent memory and was a most interesting raconteur. I enjoyed listening to, and being inspired by, many stories during my stay at Penn. I had the distinct pleasure of visiting Mildred at her home in Philadelphia this past August. We spent an hour and a half chatting about many matters of mutual interest. She was in fine fettle, and it was a joy to see every bit of the raconteur I admired and loved so much. Her passing away leaves an irreplaceable void for me. 

B. D. Nageswara Rao
Professor of physics
Indiana University-Purdue University Indianapolis


My interactions with Mildred date back to the 1970s when I became a postdoc in the laboratory of Ernie Rose at Fox Chase Cancer Center. She was very cordial, intellectually stimulating and already a legend, making her a bit intimidating for me at the beginning of my career. Our interactions became much more personal when I found myself on the verge of divorcing and becoming a single parent. Mildred stepped in, had me to dinner at her home, and more or less took me under her wing. This friendship/mentorship was to endure for many decades, through Mildred’s sabbatical to Berkeley and the decades that followed.

Our interests in stable isotopes and their use in reaction mechanisms and enzymology were one thing that drew us together. A second was the never-easily-answered question of how to raise a family and be active in science. Mildred will always be my heroine in this regard. Lastly, there was the bond of two women who became friends and cared about each other. I have one particularly fond memory of introducing Mildred, who was visiting her family in California, to my mother who had moved to California. My mother insisted that we make cookies together, and I don’t think Mildred liked being ordered around by my mother in the kitchen at all. Both Mildred and my mom are now gone, and I can only smile broadly when I think about this moment.

I am deeply saddened by the loss of Mildred. She was truly a grand lady— in every way. 

Judith Klinman
Professor of molecular and cell biology
University of California, Berkeley


In 1960, when Mildred Cohn and Henry Primakoff were contemplating moving to the University of Pennsylvania because Henry had been offered a great professorship in physics, Mildred approached Lucile Smith and I (we were the only two female faculty members in what was then the Johnson Foundation for Medical Physics) to ask how we felt women were treated at Penn. Lucile had moved to Dartmouth Medical School and had not been happy with her experiences at Penn. However, I responded that, although the director, Britton Chance, was a tough taskmaster, he was equally fair to both women and men. When the chairman of the department of biochemistry (Samuel Gurin) indicated he did not want a female faculty member in his department, Brit was delighted to welcome Mildred to his faculty. 

Helen C. Davies
Professor of microbiology
University of Pennsylvania School of Medicine

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