Capillary zone electrophoresis (CZE) is a relatively new technique for the separation of small amounts of complex mixtures of biomolecular compounds. Used generally as an analytic technique, the remarkable sensitivity of CZE recommends it in a variety of applications to studies of molecules of biological interest. Attempts to increase the sensitivity of CZE instrumentation will focus on use of even finer capillaries than those in use currently. As the width of the capillaries approaches the wavelength of light, the role of photon wavelength, of the angle of photon incidence and of capillary imperfections will become of crucial importance. The work funded through this award will investigate these effects with the aim of establishing (practical as well as theoretical) limits to capillary size with respect to both sensitivity and reproduciblity.