1921-

American biochemist who was the first to isolate transfer RNA, which plays an essential part in intracellular protein synthesis. In the late 1950s he isolated various types of RNA molecules from cytoplasm and demonstrated that each type can combine with only one specific amino acid. He obtained his M.D. degree in 1948 from Harvard University Medical School and conducted research as a fellow of the American Cancer Society, Dartmouth Medical School, and the Worcester Foundation for Experimental Biology.