Gilbert, Walter (1932- ), an American molecular biologist, shared the 1980 Nobel Prize in chemistry with Frederick Sanger of the United Kingdom for their contribution to the determination of base sequences in the nucleic acids DNA (deoxyribonu-cleic acid) and RNA (ribonucleic acid).

Gilbert discovered a method of determining the precise sequence of nucleotides (nucleotides are the principal constituents of nucleic acid and determine the structure of genes). American biochemist and molecular biologist Paul Berg also shared the Nobel Prize in 1980 for his work with recombinant DNA.

Gilbert was born in Cambridge, Massachusetts, in 1932. His father, Richard, was an economist and his mother, Emma Cohen, was a child psychologist. Gilbert was schooled at home in his early years. In 1939, the family moved to Washington, D.C., where Gilbert attended public schools and later Sidwell Friends High School. Gilbert had a strong interest in science from a young age. As a teen-ager, he won a regional science fair by creating a telescope that could photograph sunspots.

Gilbert attended Harvard University, where he earned his Bachelor of Arts degree in 1953 and his master's degree in physics in 1954. He earned his Ph.D. degree in mathematics from Cambridge University in England in 1957. He returned to Harvard as a postdoctoral fellow in physics and was appointed an assistant professor in 1959. He would remain at Harvard until 1981, when he left academia to pursue a business venture.

At Harvard, Gilbert became reacquainted with biologist James Dewey Watson, whom he had met at Cambridge in the 1950's. Gilbert and Watson worked together on a project to isolate messenger RNA, an unstable nucleic acid that carries genetic information from DNA to ribosomes. Inspired by this work, he began to redirect his career from physics to molecular biology, working hard to compensate for his lack of formal training in the field.

In the mid-1960's, Gilbert began investigating the mechanism that activates or turns on the genes governing the production of a particular protein. Working with the bacterium Escherichia coli, he and a colleague, Benno Muller-Hill, isolated the repressor molecule known as the lac repressor. Further research allowed Gilbert to discover the region of DNA to which the lac repressor binds. This in turn led to his later work on chemical sequencing, or describing chemically, a strand of DNA—the work for which he won the Nobel Prize.

In the 1970's, Gilbert began discussions with a variety of companies who wanted to capitalize on recombinant DNA research. In 1978, he and a group of other scientists established Biogen N.V., a Swiss-based genetic engineering company. Gilbert was chairman of the scientific board of directors. During his tenure at Biogen, the company succeeded in synthesizing alpha interferon, a substance thought to have cancer-fighting properties.

After a leave of absence to run Biogen, Gilbert returned to Harvard in 1985. He resumed teaching and in 1987 was appointed chair of the department of cellular and developmental biology. He also continued his research on gene structure and on the production of proteins from recombinant organisms. In the late 1980's, he became a supporter of the Human Genome Project, whose goal was to sequence and map the entire human genome, or the 46 human chromosomes.

In 1992, Gilbert founded a private company called Myriad Genetics, Inc. Myriad was involved in the efforts to sequence the human genome. In 1996, he became chief executive officer of Net-Genics, a pharmaceutical biotechnology company. In 2001, he took a leave of absence from Harvard to join a venture capital firm called BioVentures Investors, based in Cambridge, Massachusetts.

Gilbert has been granted honorary degrees by Columbia University, the University of Chicago, and the University of Rochester. In 1991, he was made an honorary fellow of Trinity College, Cambridge University. He is a member of the National Academy of Sciences, the American Academy of Arts and Sciences, the American Society of Biological Chemists, and the American Physical Society. He is a foreign member of the British Royal Society.

Gilbert has received numerous awards in addition to the Nobel Prize. In 1968, he received the U.S. Steel Foundation Award in Molecular Biology of the National Academy of Sciences. In 1979, with Frederick Sanger, he received the Albert Lasker Basic Medical Research Award. He was granted the New England Entrepreneur of the Year award in 1991.