American doctors and scientists began investigating the uses of fluorescence in medicine in the 1920s and 1930s. In the 1940s, then, when working with antimalarial drugs, the Goldwater group already knew that Atabrine and other drugs fluoresced at certain ultraviolet wavelengths just outside the visible range.

Indeed, other organic, or carbon-containing, compounds also fluoresce when irradiated by a light of the correct wavelength. After the 1950s, the SPF gave rise to many new uses for fluorescence in medical research. Today, fluorescence microscopes use sensitive electronic cameras to observe directly in three dimensions how cells function. Recently, advances in pulsed lasers have provided selective excitation of fluorescence in many tiny regions inside living cells and the ability to detect events lasting less than a trillionth of a second in proteins. Hundreds of new fluorescent dyes are available to light up specific targets, and fluorescent-activated cell sorters can be used to separate white blood cells from other cells found in blood. Using fluorescence might yield surprising new results in the future of medicine.