"Protein adsorption to material surfaces causes problems in numerous technological and medical applications. A favoured approach in order to prevent protein adsoprtion is to decorate surfaces with brushes of terminally anchored, neutral water soluble polymers (NWSP). But despite the great importance of NWSP-functionalization in medicine and technology, the interaction of proteins with NWSP is not fully understood. In particular, little is known about the mechanisms responsible for regularly observed ""brush failure"", where protein adsorption occurs despite NWSP functionalization. Here, we propose a systematic investigation of this phenomenon on a detailed structural level. Proteins interacting with NWSP-decorated surfaces of defined characteristics (i.e., polymer length and grafting density) will be localized using the combination of two sophisticated scattering techniques:1) Neutron reflectometry (NR) with contrast variation.2) Standing-wave x-ray fluorescence (SWXF).Both techniques possess un-matched spatial resolution and unique, yet complementary, chemical sensitivity. Their combination will reveal the contribution of different interaction modes of proteins with NWSP-decorated surfaces on a quantitative level. The results will provide an invaluable basis for the ""rational design"" of protein-repellent surface functionalization."