After completing his graduate studies, Berg spent two years as a postdoctoral fellow with the American Cancer Society, working at the Institute of Cytophysiology in Copenhagen, Denmark and the Washington UniversitySchool of Medicine, and spent additional time in 1954 as a Scholar in Cancer Research with the Department of Microbiology at the Washington University School of Medicine. He worked with Arthur Kornberg, while at Washington University. Berg was also tenured as a research fellow at Clare Hall, Cambridge. He was a professor at Washington University School of Medicine from 1955 until 1959. After 1959, Berg moved to Stanford University, where he taught biochemistry from 1959 until 2000 and served as director of the Beckman Center for Molecular and Genetic Medicine from 1985 until 2000. In 2000 he retired from his administrative and teaching posts, continuing to be active in research.
Research interests
Berg's postgraduate studies involved the use of radioisotope tracers to study intermediary metabolism. This resulted in the understanding of how foodstuffs are converted to cellular materials, through the use of isotopic carbons or heavy nitrogen atoms. Paul Berg's doctorate paper is now known as the conversion of formic acid, formaldehyde and methanol to fully reduced states of methyl groups in methionine. He was also one of the first to demonstrate that folic acid and B12 cofactors had roles in the processes mentioned. Berg is arguably most famous for his pioneering work involving gene splicing of recombinant DNA. Berg was the first scientist to create a molecule containing DNA from two different species by inserting DNA from another species into a molecule. This gene-splicing technique was a fundamental step in the development of modern genetic engineering. After developing the technique, Berg used it for his studies of viral chromosomes. Berg is currently a Professor Emeritus at Stanford. As of 2000, he stopped doing active research, to focus on other interests, including involvement in public policy for biomedical issues involving recombinant DNA and embryonic stem cells and publishing a book about geneticist George Beadle. Berg is a member of the Board of Sponsors of The Bulletin of the Atomic Scientists . He was also an organizer of the Asilomar conference on recombinant DNA in 1975. The previous year, Berg and other scientists had called for a voluntary moratorium on certain recombinant DNA research until they could evaluate the risks. That influential conference did evaluate the potential hazards and set guidelines for biotechnology research. It can be seen as an early application of the precautionary principle.
Awards and honors
Nobel Prize
Berg was awarded one-half of the 1980 Nobel Prize in Chemistry, with the other half being shared by Walter Gilbert and Frederick Sanger. Berg was recognized for "his fundamental studies of the biochemistry of nucleic acids, with particular regard to recombinant DNA", while Sanger and Gilbert were honored for "their contributions concerning the determination of base sequences in nucleic acids."