Tsuneko Okazaki: key obituary facts
Is Tsuneko Okazaki dead? Yes. Tsuneko Okazaki died on September 22, 2026, at age 93.
Cause of death: Tsuneko Okazaki's cause of death was reported as Gastrointestinal bleeding.
What was Tsuneko Okazaki known for?
She was a Japanese molecular biologist (1933–2026).
More about Tsuneko Okazaki
Born: 7 June 1933.
Place of birth: Nagoya.
Place of death: Nagoya.
Gender: female.
Occupation: biologist, geneticist, molecular biologist, university teacher, professor.
Nationality: Japan.
Education: Nagoya University, Aichi Prefectural Asahigaoka Senior High School.
Employer: Nagoya University, Fujita Health University.
Awards: L'Oréal-UNESCO Award For Women in Science, Person of Cultural Merit, Order of Culture, Medal with Purple Ribbon, The Order of the Sacred Treasure, Gold Rays with Neck Ribbon.
Spouse: Reiji Okazaki.
Also known as: Okazaki Tsuneko.
Known for: Okazaki fragments.
Tsuneko Okazaki, the Japanese molecular biologist known for her work on DNA replication, died of gastrointestinal bleeding on September 22, 2026, aged 93.
Born in Nagoya in 1933, she studied biology at Nagoya University and received her PhD there in 1956. That year, she met Reiji Okazaki; they married and later conducted research together.
Their early work examined DNA synthesis and nucleotide characteristics in frog eggs and sea urchins. It led to the discovery of thymidine-diphosphate rhamnose, a sugar-linked nucleotide, and helped open opportunities for research in the United States. The couple worked at the University of Washington and Stanford University in the laboratories of J. L. Strominger and Arthur Kornberg. Okazaki became known internationally for the discovery of Okazaki fragments, short DNA segments formed during replication, in work carried out with her husband. The finding helped clarify how DNA is copied, with its two strands synthesized in different ways. Okazaki continued to be involved in academia and contributed to further DNA research. Her work on replication and the fragments that bear the couple’s name remained central to her scientific legacy.