Unwanted protein adsorption is a problem in many areas of biotechnology and medicine where biological samples contact the surface of a material. This thesis has employed self-assembled monolayers (SAMs) of controlled composition to examine the influence that specific chemical interactions have on the protein adsorption characteristics of a surface. Specifically, the effects of surface hydrophilicity and of conformational mobility were examined using a series of mixed SAMs formed on gold, where one component included a terminating oligo(ethylene glycol) (OEG) tail group and the other was a simple unsubstituted n-alkyl chain used to modulate the surface energy of the mixed SAM and the free space available to the OEG tail group. The composition of the surface was easily varied by changing the ratio of alkanethiols in a solution used to form the SAM. The resulting mixed SAMs were characterized by wetting measurements using water, ellipsometry to determine film thickness, and x-ray photoelectron spectroscopy (XPS) to determine composition. (Abstract shortened by UMI.)