Christian Boehmer Anfinsen, Jr., was born 26 March 1916 in Monessen, Pennsylvania, a small town south of Pittsburgh. His father, Christian Boehmer Anfinsen, Sr., was a mechanical engineer; both he and his wife, Sophie Rasmussen Anfinsen, were Norwegian immigrants who taught their children the Norwegian language and heritage. After living for several years in the Pennsylvania town of Charleroi, the family moved to Philadelphia in the 1920s. In 1933, Anfinsen was admitted to Swarthmore College on a scholarship, where he studied chemistry and played football while working as a waiter in the dining hall. The 1937 edition of the Halcyon, the Swarthmore yearbook, described him this way: "With nostrils distended (denoting passion) [Anfinsen] strolls around campus under a mop of flaxen hair looking soulfully at the co-eds with big blue eyes." Reminiscing about his college years in 1964, Anfinsen noted humbly that "Everyone at Swarthmore was a genius except me."
After receiving his B.S. degree in chemistry in 1937, Anfinsen pursued graduate study at the University of Pennsylvania, where he worked toward a M.S. degree in organic chemistry in 1939 while serving as an assistant instructor. In 1939, the American Scandinavian Foundation awarded Anfinsen a fellowship to develop new methods for analyzing the chemical structure of complex proteins, namely enzymes, at the Carlsberg Laboratory in Copenhagen, Denmark. The dangerous environment created in Europe after the outbreak of World War Two, however, made it necessary for him to return to the United States in 1940. Alan Schechter, one of Anfinsen's postdoctoral students and later an NIH colleague, observed that Anfinsen "had the chance to see and understand the horrors then gripping Europe. His unusually deep and active sense of social responsibility certainly dated from that period, if not earlier."
In 1941, Anfinsen was offered a university fellowship for doctoral study in the Department of Biological Chemistry at Harvard Medical School. In November of that year, he married his first wife, Florence Bernice Kenenger, with whom he had three children. Anfinsen received his Ph.D. in biochemistry in 1943 after completing his dissertation, "Quantitative Histochemical Studies of the Retina," which also served as the basis of his first published article. Anfinsen taught courses in biological chemistry at Harvard until 1950.
In 1950, the National Heart Institute, one part of the rapidly expanding National Institutes of Health in Bethesda, Maryland, recruited Anfinsen as chief of its Laboratory of Cellular Physiology. In 1954, a Rockefeller Foundation fellowship enabled Anfinsen to return to the Carlsberg Laboratory in Copenhagen for a year with Kaj Linderstrøm-Lang, and a Guggenheim Foundation fellowship allowed him to study at the Weizmann Institute of Science in Rehovot, Israel, in 1958-59.
In 1962, Anfinsen returned to Harvard Medical School as a visiting professor, and was promptly invited to become chair of the Department of Biological Chemistry. The NIH, however, wooed Anfinsen back to Bethesda. He was appointed Chief of the brand new Laboratory of Chemical Biology at the National Institute of Arthritis and Metabolic Diseases (now the National Institute of Arthritis, Diabetes, and Digestive and Kidney Diseases), where he remained until 1981. In 1972, Anfinsen was awarded the Nobel Prize in Chemistry on the basis of groundbreaking work in protein chemistry that he had conducted since the early 1950s. He shared the prize with Stanford Moore and William H. Stein, both at Rockefeller University.
In 1978, Anfinsen and his wife were divorced. The following year, he married Libby Esther Shulman Ely and converted to Orthodox Judaism, a commitment he retained for the rest of his life. "Although my feelings about religion still very strongly reflect a fifty-year period of orthodox agnosticism," Anfinsen wrote in 1985, "I must say that I do find the history, practice and intensity of Judaism an extremely interesting philosophical package." In 1981, Anfinsen was offered the position of chief scientist of Taglit, a scientific research company formed by Yeda, the corporate arm of the Weizmann Institute, and the U.S. investment firm E. F. Hutton. Two weeks after the Anfinsens arrived in Israel, however, E. F. Hutton withdrew its funding from the project, leaving the couple in limbo. Anfinsen "stuck out the forced inactivity for about a year," as he observed a few years later, "but finally, needing some kind of active scientific base, wrote to friends at the Johns Hopkins University." In 1982, the university offered him a senior position as Professor of Biology and Assistant to the President for Industrial Liaison. From 1983 until 1995, Anfinsen's primary research concerned the study of "hyperthermophilic bacteria," microorganisms that thrive at extremely high temperatures.
Throughout his distinguished career Anfinsen received numerous professional honors, including memberships in the American Philosophical Society, the Royal Danish Academy, and the Vatican's Pontifical Academy of Science. From 1962, he served on the Weizmann Institute's board of governors. He was an editor of the journal Advances in Protein Chemistry, and served on the editorial committees of both the Journal of Biological Chemistry and Proceedings of the National Academy of Sciences. He also focused considerable energies on a wide range of social and political issues including nuclear disarmament, environmental depredation, and human rights abuses committed against scientists in foreign nations. Aside from his many professional and scientific responsibilities, Anfinsen played viola and piano for relaxation. He was also an avid sailor and took regular excursions on his boat around the Chesapeake Bay and along the eastern seaboard from Boston to Miami. On 14 May 1995, Anfinsen suffered a heart attack and died at Northwest Hospital Center in Randallstown, Maryland, less than a year before his 80th birthday.