One of the central tenets of quantum mechanics is the wave-particle duality. It tells us that even massive objects behave like both particles and waves. A number of previous experiments have shown this for electrons, neutrons, atoms and even large molecules. Quantum theory maintains that this is a universal property of matter. However, it had been notoriously difficult to extend this research to complex biomolecular systems. New experiments at the University of Vienna, supported by quantum chemical modelling at Stanford University now demonstrate for the first time the quantum wave nature of a complex antibiotic polypeptide, here gramicidin. The results have been published in Nature Communications.