Cover Picture: Increasing the Complexity of Periodic Protein Nanostructures by the Rolling‐Circle‐Amplified Synthesis of Aptamers (Angew. Chem. Int. Ed. 1/2008)

A self-inking roller can be used to print an extended strip with periodic repeating units. In the same way, by the biochemical technique of rolling-circle amplification (RCA), a circular oligonucleotide sequence serves as a template for the synthesis of a complementary single-stranded DNA chain. If the DNA chain contains aptamers for a protein such as thrombin or lysozyme, subsequent complexation results in periodic protein–DNA composites. I. Willner et al. describe such compounds and even assemblies of DNA, protein, and gold nanoparticles on pp. 126 ff.