Practice question

Flow cytometry evolved from principles of Coulter volume sensing and fluorescence detection of single cells in fluid stream. Mack Fulwyler in 1965 described the first fluorescence based cell sorter separating cells by volume, publishing electrostatic deflection principle that became foundation of modern instruments at Los Alamos. Engvall and Perlmann developed ELISA methodology, Rosalyn Yalow pioneered radioimmunoassay for insulin measurement. Fulwyler innovation enabled hydrodynamic focusing, laser interrogation and charged droplet sorting, allowing quantitative analysis of size, granularity and fluorescence at thousands of cells per second.