First Person | Mildred Cohn
Erica P. Johnson
Biochemist Mildred Cohn, 90, is one of the few women whose portrait hangs in the halls of the University of Pennsylvania's John Morgan Building. Retired from research but not from science per se--"I still like to talk science and I read"--Cohn is a small, reserved woman who never let the timing of her birth stand in her way. Her determination got her into college at 14, into Nobel laureate Harold Urey's lab as a student, and later to fellow winner Vincent duVigneaud's lab, where she stayed for nine years. When her fellow chemists at Columbia University learned that duVigneaud had hired her, everyone, she says, shook her hand. "It was so rare for anyone to get an academic job. This was only a postdoc position, you understand."
Cohn's 160-plus papers, including those that she co-authored with six
Nobel Laureates, covered research on isotopes, ATP, and oxidative phosphorylation. And she's still writing. Over the past few years, when invited, she's written historical perspectives, a task that she has found delightful.
What is your earliest memory?
I must have been three or older. I was riding in a horse and carriage. My father and uncle were in the front seat. My uncle was driving and the horse sat down in the road, and I was terrified. I had never seen a horse sit down.
Was your family supportive of your career choice?
My mother was not, my father was. My mother thought I should be a school teacher .... [My father] said I could be anything I wanted to be. I was participating in a panel discussion of women scientists. The only thing that all these women had in common ... was that all their fathers [were supportive].
You and your husband of 45 years, University of Pennsylvania physicist Henry Primakoff, raised three children while you pursued your career. He also supported you?
My husband and I respected each other. He assumed that I would have a career. He never took a job where I couldn't get work.
How did you choose your field?
I chose the man rather than the field; I chose Harold Urey. He worked on isotopes. The"first problem he gave me was to separate carbon 12 from carbon 13, but that didn't work out. I almost quit. For a year I had been working on that problem, and he didn't have the mass spectrometer. It was being built.
Tell us your favorite Columbia University story.
Columbia had a very good chemistry department, 75 candidates in its PhD program. This was [before the] war. The big industrial chemical companies sent around recruiters ... the announcement would go up on the bulletin board, and it always read the same thing: "Mr. So-and-So from such-and-such company will interview all prospective PhDs of this year. Male Christian." I was out on two counts. I never got an interview.
What was stressful for you years ago?
To see that my children were properly taken care of, especially during WWII. I did have great difficulty in New York; you couldn't put a child in nursery school until [the child was] three years old. When I went to St. Louis, [Washington University] ... I got someone who stayed with me for the next 30 years. She really brought up my third child.
What is stressful now?
What were your most exciting scientific moments?
In 1958, using nuclear magnetic resonance, I saw the first three peaks of ATP.1 That was exciting. [I could] distinguish the three phosphorous atoms of ATP with a spectroscopic method, which had never been done before. Another paper, in 1962, was about the effect of metal ions on the phosphorous spectrum of ATP.2 And earlier, I found that oxygen in inorganic phosphate exchanged with water through oxidative phosphorylation.3
What would you have done differently?
Maybe be born in a different time. It takes everything out of you [to overcome adversity].
What are your views about the politics regulating science?
I think ignorance is the worse thing. We know that scientific discoveries can be abused, but on the other hand I think the benefits of something like stem cell research far outweigh the disadvantages. Scientists have more trouble communicating their ideas to the public than the politicians do, so I think it's important for scientists to be able to present their views to the public in as objective a way as they can, and not for their own self-fulfillment.
1. M. Cohn, T.R. Hughes, "Phosphorus magnetic resonance spectra of adenosine diphosphate and triphosphate. I. Effect of PH," J Biol Chem, 235:3250-3, 1960.
2. M. Cohn, T.R. Hughes, "Nuclear magnetic resonance spectra of adenosine di- and triphosphate. II. Effect of complexing with divalent metal ions," J Biol Chem, 237:176-81, 1962.
3. M. Cohn, "A study of oxidative phosphorylation with 0-18 labeled inorganic phosphate," J Biol Chem, 201:735-50, 1953.