In my group we study bacterial polysaccharides and their protein interaction partners. Special emphasis lies on bacteriophage infection mechanisms mediated by glycan structures. For this, we also investigate structural thermodynamics of complex carbohydrate recognition by bacteriophage proteins. We analyze protein-carbohydrate interactions with isothermal titration calorimetry, surface plasmon resonance and spectroscopic techniques. Viral adhesion proteins recognizing polysaccharides of Gram-negative bacteria serve as a model system. These tailspike proteins bind to lipopolysaccharides, the essential receptors of O-antigen specific bacteriophages. Moreover, tailspikes are also promising tools to develop agents to control biofilm and for pathogen detection.