Merrifield, Robert Bruce (1921-) is an American biochemist who won the 1984 Nobel Prize in chemistry for his method of producing peptides and proteins. He revolutionized the study of these complex materials by developing an automated laboratory technique for rapidly synthesizing peptide chains in large quantities, thus greatly advancing the fields of biochemistry, molecular biology, and pharmacology.

He attended Pasadena Junior College and then transferred to the University of California at Los Angeles (UCLA), graduating in 1943. He then worked for a year at the Philip R. Park Research Foundation where he assisted with growth experiments feeding test animals a synthetic amino acid diet. He earned his Ph.D. degree at the University of California at Los Angeles in 1949. He then joined the Rockefeller Institute for Medical Research (now Rockefeller University) in New York City, where he studied proteins.

The large protein molecules called polypeptides are chains of the chemical building-blocks known as peptides. Each peptide consists of a chain of several hundred amino-acid molecules. In 1959, Merrifield developed a method to create polypeptides called solid-phase peptide synthesis. The method involved binding the first of the many amino acid residues, of which a protein is composed, to a solid matrix called a polymer. By anchoring the peptide chains on the polymer, the many time-consuming intermediate steps that had been involved in the traditional methods of creating polypeptides were eliminated. By 1965, he developed a machine that synthesized this process automatically. Solid-phase peptide synthesis has facilitated the development of new drugs and gene technology. By the mid-1960's, he synthesized the hormone bradykinin, which dilates blood vessels, and the protein insulin, which is used in the treatment of diabetes.