Dorte G. Simmons, 70, a retired microbiologist and laboratory worker at Georgetown University and the American Type Culture Collection, died June 13 at her home in Potomac. She had brain cancer, said her husband, Walter Simmons.

Mrs. Simmons worked at Georgetown for several years before joining ATCC, a nonprofit biological research organization, in 1995. She worked there as a microbiologist until her retirement in 2005.

Dorte Gerecke was born in Halberstadt, Germany, and attended the University of Kiel in Germany. She came to Washington in 1965 to study English.

She was interested in Asian art and traveled widely. She was a member of the Japanese Art Society of America and the Friends of the Freer and Sackler Galleries.

Survivors include her husband of 45 years, Walter P. Simmons III of Potomac; three children, Walter P. “Pete” Simmons IV and Christine Wain, both of the Rocky Gorge section of Howard County, and Eric Simmons of Walnut Creek, Calif.; and six grandchildren.

— Matt Schudel