Editor's note: Citation Classics Commentaries were written by the authors of studies that were some of the most highly cited papers between 1961 and 1975. The essays were originally published between 1977 and 1993 in Current Contents, a publication of the Institute for Scientific Information (ISI), now Thomson Scientific. (ISI was founded by Eugene Garfield, also the founder of The Scientist.) In this essay, published in 1977, a virologist recalls his 1958 paper describing a modified technique for immunofluorescence.
Immunoflourescence originally used isocyanate as a dye, an unstable substance that required the poisonous gas phosgene in its preparation. As a graduate student at the University of Kansas in the laboratory of Joseph Burckhalter, John Riggs worked out how to replace phosgene with thiophosgene, a less toxic gas, to synthesize a more stable dye, fluorescein isothiocyanate (or FITC). The paper was cited 546 times between 1961 and ...
