DNA assists self-assembly
Both teams mix two populations of nanoscale gold spheres, A (red) and B (blue) that have long DNA strands covalently grafted onto their surfaces. The ends of these strands contain complementary sequences. When A and B are close together, the ends hybridize into a double helix, forming bridges that pull the spheres together. b, The spheres self-assemble into large, ordered "caesium chloride" arrays with a body-centred-cubic symmetry; one unit cell is shown. Credit: Nature