Arthur Kornberg (1918-2007) was an American biochemist who made outstanding contributions to molecular biology through his research on enzymes. He was the first to isolate DNA polymerase, the enzyme that assembles DNA from its components, and the first to synthesize DNA in a test tube, which earned him a Nobel Prize in 1959. He later became the first to replicate an infective virus DNA in vitro. Kornberg was also the first chairman of the Department of Biochemistry at the Stanford University School of Medicine, which under his guidance became a preeminent center for DNA research, including recombinant DNA research.