Professor Gest was born in London, England and emigrated with his family to the US when he was one year old. During undergraduate studies at UCLA (B.A., 1942) he spent two summers assisting Max Delbruck and Salvador Luria doing research on bacterial viruses at the Cold Spring Harbor Laboratory (New York). In 1942, Gest began graduate work with Delbruck at Vanderbilt University, but World War II interrupted his studies. He accepted a position on the Manhattan Atomic Bomb Project with the eminent physical chemist Charles Coryell. Their research focused on characterization of the radioactive elements formed in uranium fission. After World War II ended, Gest completed graduate work (Ph.D. 1949) at Washington University (St. Louis) as the first student of Martin Kamen, a pioneer nuclear chemist renowned as the co-discoverer of carbon 14. During that period, Gest also researched with Alfred Hershey on the fate of radioactive phosphorus during the multiplication of bacterial viruses. The latter culminated in the discovery of "P-32 suicide" of bacteriophage. Prior to 1950, Gest had worked with Delbruck, Luria and Hershey, who shared a Nobel Prize in 1969.
Gest was on the faculties of Case Western Reserve University and Washington University. He was a visiting researcher at the California Institute of Technology, Dartmouth Medical School, Stanford University, Oxford University, Tokyo University, and UCLA. Professor Gest was a Guggenheim Fellow twice and served on a number of advisory committees of the US Government. He is widely recognized for his research on microbial physiology and metabolism, especially with photosynthetic bacteria. Gest was a Fellow of the American Association for the Advancement of Science, American Society for Microbiology, American Academy of Microbiology, and the American Academy of Arts and Sciences.