Kornberg, Arthur (1918-), an American physician and biochemist, was the first to discover how molecules of deoxyribonucleic acid (DNA) duplicate within bacterial cells and also the first to devise a method for synthesizing this process in a laboratory setting. For these achievements he shared the 1959 Nobel Prize in physiology or medicine with Severo Ochoa.

After graduating from high school at the age of 15, Kornberg received a state scholarship to attend City College of New York. Taking the premedical track, he majored in chemistry and biology and earned his B.Sc. degree in 1937. He entered medical school at the University of Rochester, again with the help of a scholarship, and it was during this time that he first became fascinated with collecting data and doing research. Also while in medical school, he published his first professional paper, on the subject of jaundice, in the Journal of Clinical Investigation.

Kornberg received his M.D. degree in 1941 and then began an internship at Strong Memorial Hospital, an affiliate of the University of Rochester. With the outbreak of World War II (1939–1945), he served as a commissioned officer in the U.S. Public Health Service. He was transferred to the nutrition section of the Division of Physiology at the National Institutes of Health (NIH) and from 1947 served as head of the enzyme and metabolism section, a position he held through 1952. In the late 1940's and early 1950's, Kornberg broadened his experience in the area of enzyme biochemistry through working for a year first with Severo Ochoa at the New York University College of Medicine and then another year with Carl Ferdinand Cori and Gerty Theresa Cori at the Washington University School of Medicine in St. Louis, Missouri. He also did research at the University of California at Berkeley.

Leaving NIH in 1953 to become chairman of the department of microbiology at Washington University in St. Louis, Missouri, Kornberg continued to focus his research on enzyme chemistry. At Washington University, he began to investigate the way in which nucleotides, the “building blocks” of the large DNA and RNA (ribonucleic acid) molecules, are polymerized, or linked together. The order in which nucleotides combine in DNA determines hereditary traits in everything from human life to viruses and bacteria, and Kornberg's initial objective was to find a way to replicate this process. In 1956, he and his team discovered an enzyme they named DNA polymerase, which turned out to be the catalyst for the replication and repair of DNA.

By the following year, using a preexisting animal DNA molecule as a template, Kornberg succeeded in creating a synthetic duplicate by mixing together the DNA polymerase enzyme and the four nucleotide building blocks with the template DNA. Although the synthetic strand of DNA was not genetically active, the feat did prove definitively that the DNA polymerase was responsible for the production of new strands of DNA. It also indicated the way in which the pattern of nucleotides from the original strand is duplicated. In 1959, Kornberg won his Nobel Prize for this achievement and the same year moved to Stanford University in Palo Alto, California, to serve as head of the biochemistry department.

At Stanford, Kornberg concentrated on creating a genetically active synthetic DNA, and in 1967, with collaborator Mehran Goulian, finally achieved his objective. Using purified DNA polymerase and a simplified DNA template—the single-stranded virus Phi X174—they were able to create an exact but artificial duplicate. When the synthetic DNA was introduced into a culture of Escherichia coli cells, the effects were nearly immediate. As soon as the artificial virus began to infect the E. coli cells, they in turn ceased their normal genetic activity and began instead to create duplicates of the synthetic Phi X174 virus. This activity proved that the laboratory-manufactured DNA had become a sec-ond-generation template, functioning precisely as did the natural DNA.

The significance of this success was that it opened the door to the development of recombi-nant DNA technology and genetic engineering. Widespread use of Kornberg's revolutionary processes have allowed for the development of most of the chemotherapeutic agents being used today to treat cancers, autoimmune diseases, and viral infections such as AIDS.

As a Nobel laureate, Kornberg has spoken up for numerous causes and has often collaborated on his work with his wife, also a biochemist. As professor emeritus, he remains active in research at Stanford's Center for Molecular and Genetic Medicine. His son Roger is also a professor at Stanford, in the structural biology department.