Meselson, Matthew Stanley

AbstractThe article highlights Meselson's unique position in science and society as an innovative scientist involved in several ‘crucial experiments’ in molecular biology; a policy analyst in the domain of biological and chemical weapons for US administrations in the 1960s and 1970s; and a public intellectual shaping the public opinion against the use of such weapons in both war and peace times. Meselson's role in the ‘Meselson–Stahl experiment’ (hereafter the ‘M–S experiment’) which established the semiconservative mode ofdeoxyribonucleic acid (DNA)replication for which both Meselson and Stahl remain best known, is highlighted.Meselson's role as a public intellectual is discussed mainly in terms of his sustained refutation of the US claim in the 1970s that its East Asian enemies used chemical weapons on civilians in the form of ‘yellow rain’. Meselson's association with Caltech in the 1950s and Harvard, since 1960, is discussed as a pertinent institutional context for his scientific and policy activities.