Stanley N. Cohen

Stanley N. Cohen is an American geneticist at Stanford University School of Medicine who, with Herbert Boyer, was among the first scientists to transplant genes from one living organism into another, establishing a foundational technique of genetic engineering. In 1973 Cohen and Boyer published a landmark paper describing the construction of biologically functional bacterial plasmids in vitro, demonstrating that a gene from an unrelated organism, in their key experiment a frog ribosomal RNA gene, could be inserted into a bacterial plasmid and expressed inside the bacterium. Cohen and his collaborators developed the plasmid pSC101 as a vector for carrying foreign genes into bacterial cells, a tool that became widely used across the emerging field of recombinant DNA research. Unlike Boyer, Cohen chose not to join the biotechnology company Genentech that grew out of their shared discovery, though he consulted for Cetus Corporation, another early biotechnology firm. Cohen joined the Stanford faculty in 1968, became professor of genetics in 1977, chaired Stanford's genetics department from 1978 to 1986, and received honors including the National Medal of Science in 1988 and the Wolf Prize in Medicine in 1981.