Overall, our microarray and nanoparticle binding studies with the fluorinated Lewis x glycan library reveal distinctive modes of recognition of the Lewis X trisaccharide by the monoclonal Lewis x antibodies, DC-SIGN, and bacterial toxins investigated. These different Lewis X binding proteins have different responses to the site-specific deoxy/fluorine-modifications, as summarized for the 11 individual site modifications in Table ). Deoxygenations/deoxyfluorinations are shown to either enhance or reduce affinities, with different proteins with a Lewis x binding site showing different preferences and tolerances for binding. As shown by the screening analysis of DC-SIGNR, which is closely related to DC-SIGN but does not bind to Lewis x , there was little binding to fluorinated Lewis x analogues.