Robert Ofoli Abstract The objective of this project is to use total internal reflection flourescence (TIRF) to study the adsorption of proteins at the liquid-liquid interface. TIRF provides the ability to selectively excite species at or near an interface, and enables one to quantify the adsorption and desorption kinetics. Specific aspects of the project include adaptation of the standard experimental protocol used with TIRF at the solid-liquid interface to extend its application at the liquid-liquid interface, development of a calibration technique for quantifying adsorption at the liquid-liquid interface, and equilibrium adsorption of several proteins. The TIRF experimental setup will utilize a inverted microscope, a 5 W continuous wave ion argon laser, and standard photometry. The adaptation of TIRF to the liquid-liquid interface provides a new tool that may be used to elucidate important liquid-liquid interfacial phenomena. While fundamental in nature, the study is clearly of both scientific and technological significance,and should help advance scientific understanding of protein adsorption and interactions at the liquid-liquid interface. ***