Figure 4.

Internal organization of printed materials. (A) Schematic shows how two pairs of microparticle types bearing DNA complementary to each other should form a binary mixture of red and green clusters. (B) Micrograph shows a millimeter sized assembled aggregate generated from the complementary microparticle mixture; the diagram indicates how the outer margin of the object was imaged. Scale bar is 5 mm. (C) Confocal micrograph of the edge of the aggregate shows red and green clusters. Scale bar is 50 μm. (D–F) Corresponding experiments with noncomplementary microparticles show no assembly. Scales are identical to those in A–C.