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In 1998, human embryonic stem cells were isolated for the first time at the University of Wisconsin-Madison. This was accomplished under the scientific directorship of James Thomson (born 1958), and published in the groundbreaking Science article titled “Embryonic Stem Cells Derived from Human Blastocysts.” Stem cell research was, and still is, a highly controversial field, due to the destruction of a human embryo in the process. Through careful consultation with bioethicists and the ethical acquisition of human embryos, Thomson was able to conduct his research and ultimately contribute scientific research highly beneficial to the medical world


  • Dr. James Thomson
  • Human Stem Cells

James Alexander Thomson, born in 1958, was the first person to successfully isolate human embryonic stem cells while working at the University of Wisconsin-Madison. His pioneering work was published in his 1998 Science article, titled “Embryonic Stem Cells Derived from Human Blastocysts.” Before coming to the University of Wisconsin-Madison, Thomson studied at the University of Illinois Urbana-Champaign and the University of Pennsylvania. He then did his postdoctoral research the Oregon Regional Primate Center, and it was Thomson’s move to the Wisconsin Regional Primate Center which brought him to the University of Wisconsin-Madison.

Stem cell research was highly controversial during the time in which Thomson conducted his research, and still is today. During the process of isolating stem cells, human embryos are destroyed. Many groups, mainly religious and pro-life, have questioned the ethical nature of the research. With this in mind, Thomson consulted University of Wisconsin-Madison bioethicists, Norman Frost and R. Alta Charo before attempting to isolate any stem cells in his research. He ultimately deemed that because the human embryos he used were left over from fertility clinics and would be destroyed if not used for scientific research, that his research was ethical.

Thomson’s work opened the door for groundbreaking medical research and innovation, even though at the time national policies still did not support stem cell research. The University of Wisconsin-Madison, seeing the immense potential in Thomson’s efforts, promoted him to Assistant Professor in the Department of Anatomy. The WiCell Research Institute in Madison also promoted Thomson, placing him in the positon of Scientific Director. Thomson has also won many awards for his work in the field of stem cell research, some of which are the 1990 Gold Plate Award from the Academy of American Achievement, the 2002 Lois Pope Annual LIFE International Research Award, and named one of Time magazines most influential people of 2008.

Thomson, James. “Embryonic Stem Cells Derived From Human Blastocysts.” Science 282, no. 5391 (November 6, 1998): 1145-1147.

Thomson, James A., Dr. [Oral History Program Interview with James A. Thomson, 2005]. Audio Recording.

Wu, Ke. “James Alexander Thomson (1958).” Embryo Project Encyclopedia. Last Modified February 1, 2011. Accessed November 10, 2018. http://embryo.asu.edu/handle/10776/1985.