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Maud Leonora Menten (March 20, 1879 – July 26, 1960) was a Canadian physician-scientist who made significant contributions to enzyme kinetics and histochemistry. Her name is associated with the famous Michaelis-Menten equation in biochemistry.

Maud Menten was born in Port Lambton, Ontario and studied medicine at the University of Toronto (B.A. 1904, M.B. 1907, M.D. 1911). She was among the first women in Canada to earn a medical doctorate. She completed her thesis work at University of Chicago. At that time women were not allowed to do research in Canada, so she decided to do research in other countries such as the United States and Germany.

In 1912 she moved to Berlin where she worked with Leonor Michaelis and co-authored their paper in Biochemische Zeitschrift which showed that the rate of an enzyme-catalyzed reaction is proportional to the amount of the enzyme-substrate complex. This relationship between reaction rate and enzyme–substrate concentration is known as the Michaelis–Menten equation. After studying with Michaelis in Germany she entered graduate school at the University of Chicago where she obtained her PhD in 1916. Her dissertation was titled “The Alkalinity of the Blood in Malignancy and Other Pathological Conditions; Together with Observations on the Relation of the Alkalinity of the Blood to Barometric Pressure”. Menten worked at the University of Pittsburgh (1923–1950), becoming Assistant Professor and then Associate Professor in the School of Medicine and head of pathology at the Children’s Hospital of Pittsburgh. Her final promotion to full Professor, in 1948, was at the age of 69 in the last years of her career. Her final academic post was as a research fellow at the British Columbia Medical Research Institute (1951-1953).

Early life

Little is known about her parents and childhood other than that the Menten family moved to Harrison Mills, where Maud’s mother worked as a postmistress. After completing secondary school, Menten attended the University of Toronto where she earned a bachelor of arts degree in 1904 and a master’s degree in physiology in 1907. While earning her graduate degree, she worked as a demonstrator in the university’s physiology lab.

A talented student, Menten was appointed a fellow at the Rockefeller Institute for Medical Research in New York City in 1907. There, she studied the effect of radium bromide on cancerous tumors in rats. Menten and two other scientists published the results of their experiment, producing the institute’s first monograph. After a year at the Institute, Menten worked as an intern at the New York Infirmary for Women and Children. She returned to Canada and began studies at the University of Toronto a year later. In 1911 she became one of the first Canadian women to receive a doctor of medicine degree.


Her most famous work was on enzyme kinetics together with Michaelis, based on earlier findings of Victor Henri. This resulted in the Michaelis-Menten equations. Menten also invented the azo-dye coupling reaction for alkaline phosphatase, which is still used in histochemistry. She characterised bacterial toxins from B. paratyphosus, Streptococcus scarlatina and Salmonella ssp. that were used in a successful immunisation program against scarlet fever in Pittsburgh in the 1930s – 1940s. She also conducted the first electrophoretic separation of blood haemoglobin proteins in 1944. She worked on the properties of hemoglobin, regulation of blood sugar level, and kidney function. She wrote or co-wrote about 100 research papers.

After her retirement from the University of Pittsburgh in 1950, she returned to Canada where she continued to do cancer research at the British Columbia Medical Research Institute. Poor health forced Menten’s retirement in 1955, and she died July 20, 1960, at the age of 81, in Leamington, Ontario.

Personal life

Rebecca Skloot portrays Menten as a petite dynamo of a woman who wore “Paris hats, blue dresses with stained-glass hues, and Buster Brown shoes.” She drove a Model T Ford through the University of Pittsburgh area for some 32 years and enjoyed many adventurous and artistic hobbies. She played the clarinet, painted paintings worthy of art exhibitions, climbed mountains, went on an Arctic expedition, and enjoyed astronomy. She also mastered several languages, including Russian, French, German, Italian, and at least one Native-American language. Although Menten did most of her research in the United States, she retained her Canadian citizenship throughout her life.


Throughout her career Menten was affiliated with many scientific societies.

At Menten’s death, colleagues Aaron H. Stock and Anna-Mary Carpenter honored the Canadian biochemist in an obituary in Nature: “Menten was untiring in her efforts on behalf of sick children. She was an inspiring teacher who stimulated medical students, resident physicians and research associates to their best efforts. She will long be remembered by her associates for her keen mind, for a certain dignity of manner, for unobtrusive modesty, for her wit, and above all for her enthusiasm for research.”

In 1998 she was posthumously inducted into the Canadian Medical Hall of Fame. She was also honored at the University of Toronto with a plaque and at the University of Pittsburgh with memorial lectures and a named chair. Port Lambton, Canada, where Menten was born, installed a commemorative bronze plaque about her in 2015.

Selected publications

  • Menten, ML.; Willms, M.; Wright, WD. (1953). “Nucleic acid content of splenic lymphocytes in normal and leukemic mice”. Cancer Research. 13: 729-732. 
  • Neale, AE.; Menten, ML. (1948). “Tumors of the thymus in children”. American Journal of Diseases of Children. 76: 102–108. doi:10.1001/archpedi.1948.02030030109012. 
  • Menten, ML.; Fetterman, GH. (1948). “Coronary sclerosis in infancy – report of 3 autopsied cases, 2 in siblings”. American Journal of Clinical Pathology. 18: 805–810. doi:10.1093/ajcp/18.10.805. 
  • Menten, ML.; Janouch, M. (1946). “Changes in alkaline phosphatase of kidney following renal damage with alloxan”. Proceedings of the Society for Experimental Biology and Medicine. 63: 33–37. doi:10.3181/00379727-63-15482. 
  • Troll, MM.; Menten, ML. (1945). “Salicylate poisoning – report of 4 cases”. American Journal of Diseases of Children. 69: 37–43. doi:10.1001/archpedi.1945.02020130044006. 
  • Menten, ML.; Junge, J.; Green, MH. (1944). “Distribution of alkaline phosphatase in kidney following the use of histochemical azo dye test”. Proceedings of the Society for Experimental Biology and Medicine. 57: 82-86. doi:10.3181/00379727-57-14706. 
  • Menten, ML.; Junge, J.; Green, MH. (1944). “A coupling histochemical azo dye test for alkaline phosphatase in the kidney”. Journal of Biological Chemistry. 153: 471-477. 
  • Andersch, MA; Wilson, DA; Menten, ML. (1944). “Sedimentation constants and electrophoretic mobilities of adult and fetal carbonylhemoglobin”. Journal of Biological Chemistry. 153: 301–305. 
  • King, CG.; Menten, ML. (1935). “The influence of vitamin C level upon resistance to diphtheria toxin I. Changes in body weight and duration of life”. Journal of Nutrition. 10: 129-140. 
  • Menten, ML (1927). “Changes in the blood sugar of the cod, sculpin, and pollock during asphyxia”. Journal of Biological Chemistry. 72: 249–253. 
  • Menten, ML (1922). “Pathological lesions produced in the kidney by small doses of mercuric chloride”. Journal of Medical Research. 43: 315-321. 
  • Menten, ML., “A study of the oxidase reaction with a-naphthol and paraphenylenediamine.” Journal of Medical Research, Vol 40 (1919) pp. 433 – U22
  • Michaelis L., Menten, ML. “The kinetics of invertin action” Biochemische Zeitschrift, Vol 49 (1913) pp. 335-369 (Translation by T.R.C. Boyde in FEBS Letters, vol 587 (2013) 
  • Jobling, J. W., Flexner, S., Menten, M. L. Tumors of animals New York: Rockefeller Institute for Medical Research, 1910