Our goal was to design carbohydrate mimetics capable of preventing cell adhesion of pathogens by targeting lectins. The original synthesis of these mimetics combines the automated chemistry of DNA and ''click'' chemistry. From simple building blocks (i.e. phosphoramidites, solid supports and carbohydrates such as alkyne or azide derivatives), a ''Lego'' approach provides complex and varied decoys exhibiting various topologies and number of carbohydrate residues. The resulting glycomimetics tagged with a specific DNA sequence are efficiently immobilized on a DNA microarray by double strand formation. This glycoarray allows the study of the interactions between carbohydrate mimics and lectins using a minute amount of material. This micro system using DNA arrays is much more effective than conventional carbohydrate microarrays. The studies allowed the identification of the important structural parameters for a customized construction of high-affinity carbohydrate mimics.