Marshall Warren Nirenberg was born April 10, 1927, in New York City, to Harry Nirenberg and Minerva Bykowsky Nirenberg. In 1941, Marshall developed rheumatic fever, and the Nirenberg family moved to Orlando, Florida, to take advantage of the subtropical climate. During his teens, Nirenberg developed a scientific and aesthetic appreciation for the natural world. Reminiscing about his childhood, he remarked in 1992 that "Florida was a natural paradise in those days. And I was the kind of kid who was happy exploring swamps and caves, and collecting spiders." In the Documents section, viewers can see a sketch of spiders that he made when he was 17 years old.

Nirenberg became an adept observer of plant life, insects, and birds, and captured these observations through carefully written and maintained notes. These sketches and notes presaged a career in which scientific diaries filled with thorough documentation provided a constant source of inspiration for research and analysis. In 1945, Nirenberg graduated from high school and enrolled at the University of Florida in Gainesville. He earned his B.S. degree in zoology and chemistry in 1948. In 1950, he resumed his studies at Florida and took a M.S. degree in zoology in 1952, writing a master's thesis on caddis flies.

Later that year, Nirenberg moved to Ann Arbor to attend the University of Michigan. In 1957, Nirenberg earned a Ph.D. in biological chemistry by writing a dissertation on the uptake of hexose, a type of sugar, by tumor cells. This work served as the basis of his first published article and shaped the direction of his initial studies after graduate school. In 1957, the American Cancer Society awarded Nirenberg a two-year postdoctoral fellowship to DeWitt Stetten, Jr.'s laboratory at the National Institute of Arthritis, Metabolism, and Digestive Diseases (NIAMDD), a part of the National Institutes of Health (NIH) in Bethesda, Maryland. In 1959, Nirenberg was chosen as a postdoctoral fellow of the Public Health Service's Section on Metabolic Enzymes at NIAMDD. The following year, Nirenberg joined the staff as a research biochemist.

In 1959, Nirenberg began his investigations into the relationship between deoxyribonucleic acid (DNA), ribonucleic acid (RNA) and the production of proteins. With J. Heinrich Matthaei, a young postdoctoral researcher from Bonn, Germany, he initiated a series of experiments using synthetic RNA. These two researchers were able to show how RNA transmits the "messages" that are encoded in DNA and direct how amino acids combine to make proteins. These experiments became the foundation of Nirenberg's groundbreaking work on the genetic code, which he first made public at the International Congress of Biochemistry in Moscow in August 1961. By early 1962, the significance of these early experiments was recognized throughout the world, after the popular media highlighted the importance of their work as a major scientific breakthrough.

Nirenberg's work catapulted the scientist--whom the Washington Post described as "painfully modest"--to international fame. James F. Hogg, Nirenberg's former advisor at the University of Michigan, joked in a letter that "In view of the very extensive recent publicity, we are considering putting a sign on our house, as follows 'Painted by Marshall [W.] Nirenberg' A.D. 1953. Would you please send a letter of authentication? We could then perhaps obtain a tax exemption as a historical site!" In 1962, less than one year after he had first announced his successful experiment with synthetic RNA, he received the Molecular Biology Award from the National Academy of Sciences.

During this same period, Nirenberg was offered professorships at a number of major universities across the United States. He was also offered a research position with Francois Jacob--who would become the 1965 Nobel Laureate in Physiology or Medicine--at the Institut Pasteur, one of the world's leading centers of molecular genetics. Nirenberg, however, declined all offers and chose to stay at the National Institutes of Health. A steady annual research budget, he believed, would enable him to remain devoted to his work rather than spend his time pursuing outside grants. In 1962, he was appointed Chief of the Section on Biochemical Genetics at the NIH's National Heart Institute (NHI).

After Matthaei's departure from the NIH in 1962, Nirenberg continued his work on the genetic code with a team of postdoctoral fellows and research technicians. By 1966, Nirenberg had deciphered all the RNA "codons"--the term used to describe the "code words" of messenger RNA--for all twenty major amino acids. Two years later, in 1968, Nirenberg received the Nobel Prize in Physiology or Medicine for "interpretation of the genetic code and its function in protein synthesis." He shared the award with Robert W. Holley of Cornell University and Har Gobind Khorana of the University of Wisconsin at Madison.

After Nirenberg's research on the genetic code, he turned to the field of neurobiology. Nirenberg chose neurobiology because it is the only other biological system besides the genetic code that is designed for information processing. DNA processes genetic information, and the brain processes mental information. The new scientific arena gave Nirenberg the freedom to ask new questions, solve new problems, and explore new biological puzzles. Nirenberg would devote the next thirty years of his scientific career to the investigation of various aspects of neurobiology.

Dr. Nirenberg has been honored for his work by many prestigious scientific organizations, including the National Academy of Sciences, the American Academy of Arts and Sciences, the Gairdner Foundation, and the Albert and Mary Lasker Foundation. President Lyndon B. Johnson awarded Nirenberg the National Medal of Science in 1966 and the National Medal of Honor in 1968. He is an active member of the Pontifical Academy of Sciences, part of the Vatican. He has maintained his current position as Senior Research Biochemist and Chief of the Laboratory of Biochemical Genetics at the NHI, later named the National Heart, Lung, and Blood Institute, since 1966. He also served as a research professor in molecular and cell biology at the University of Maryland at College Park, and an adjunct professor of biochemistry and molecular biology at The George Washington University Medical Center in Washington, D.C. In 2001, Dr. Nirenberg was elected to the American Philosophical Society.

Nirenberg married an NIH colleague, biochemist Perola Zaltzman, in 1961. Widowed in 2001, he married Myrna Weissman, Professor of Epidemiology and Psychiatry at Columbia University and Chief of the Department in Clinical-Genetic Epidemiology at New York State Psychiatric Institute, in 2005.

Dr. Nirenberg died January 15, 2010 of cancer at his home in New York. He also lived in Potomac, Maryland.