Anne MacGregor Perley was a biochemist who worked on the Manhattan Project at Los Alamos. She was part of Louis Hempelmann’s Health Group, one of his many recruits from Washington University in St. Louis. She had served on the faculty there and on the staff of St. Louis Children’s Hospital since 1931. She was tasked with researching detection methods for workers exposed to radiation. She was the only one who knew how to measure the radiation doses of the individuals involved in the Louis Slotin accident. She was also allowed to observe the Trinity Test, for which the Health Group prepared safety precautions. After the war, she returned to Washington University, and then moved to the University of Oregon in 1951. She continued to publish papers, especially in pediatric biochemistry, for several decades.