Nathans, Daniel (1928-1999), an American microbiologist, shared the 1978 Nobel Prize in physiology or medicine with his colleague Hamilton Othanel Smith and with Werner Arber of Switzerland. Nathans was awarded the prize for his analysis of DNA, using a restriction enzyme discovered by Smith as “biochemical scissors.” Restriction enzymes, whose existence was first predicted by Arber, provide the “chemical knives” to cut DNA into defined fragments. By making it possible to separate DNA into its component parts, Nathans's research opened up new paths for solving basic problems in developmental biology and for understanding, preventing, and treating birth defects, hereditary diseases, and cancer.

The youngest of nine children of Russian Jewish immigrant parents, Nathans grew up in poverty during the Depression, and from age 10 began working while going to school. A summa cum laude graduate of the University of Delaware, with distinction in chemistry (1950), he earned his M.D. degree from Washington University School of Medicine in St. Louis, Missouri (1954). Following his internship (1954--1955) and before his residency (1957--1959) at Columbia-Presbyterian Medical Center in New York City, he did research on the biosynthesis of proteins at the National Institutes of Health (1955--1957). An appointment as guest investigator at Rockefeller University in New York followed (1959--1962).

In 1962, he became an assistant professor of microbiology at Johns Hopkins University, where he later served as director of the departments of microbiology and of molecular biology and genetics, and as interim president (1995--1996) of the University's School of Medicine. In 1993, he received the National Medal of Science.

Nathans's discovery of "biochemical scissors," which led to such biotechnological breakthroughs as the mapping of the human genome and the production of synthetic insulin and growth hormone, earned him the nickname "father of modern biotechnology."