Chemical Kinetics and Fluorescence Correlation Spectroscopy

The dynamics of macromolecules, the subject of this symposium, are most directly studied by simply looking through a microscope and observing the molecular motion. With a microscope, we can resolve the size and shape of large particles, as well as monitor dynamic motion. For smaller particles, particularly single macromolecules, we cannot resolve the size or shape; but it is still possible to observe the motion, if we can make the particles appear as bright points of light sprinkled dilutely over a dark background. Siedentopf & Zsigmondy (1903) demonstrated this fact with a device which came to be called the ultramicroscope.