Eukaryotic membrane bound cytochrome c is believed to use areas of negative and positive charge to bind to the membrane and to interact in vivo with the corresponding oxidase and reductase. This specific charge distribution makes the protein ideal for the formation of self-assembled layers on charged surfaces. Citrate-coated, hexagonal silver colloidal particles were used to give a negatively charged surface for adsorption, and the effect of concentration and surface coverage was studied by surface enhanced resonance Raman scattering(SERRS). Excitation was with a preresonant frequency where the angular dependence of the scattering intensity is more pronounced than in resonance. The heme ring plane lies at a slight angle to the silver surface at low surface coverage. The adherence of the protein to the negatively charged surface is strong (indicated by no detectable SERRS from protein in supernatant), and as packing density is increased, a reorientation of about 5 degrees to a more vertical orientation is observed. No alteration in frequency of the principal bands can be observed, and therefore, no denaturation occurs. A more subtle change in the relative intensities suggests that there are two forms of packing with the difference in packing density determining the protein/protein orientation. Increase in pH causes reorientation of the protein to a more inclined orientation. The extent of the change is dependent upon protein packing density. Greater reorientation occurs at low densities.