Extended Data Fig. 2: Fluorescent microscope image of DNA-coated compressed tetrahedral clusters.

DNA strands are fluorescently labelled. The image shows that the single-stranded DNA can be selectively functionalized onto the TPM patches and that the polystyrene surfaces are nearly bare. Note that the polystyrene surfaces need not be completely bare of DNA strands: the areal coverage of DNA just has to be much lower on the polystyrene surfaces than on the TPM patches, so that the DNA melting temperatures for the sphere–patch or sphere–sphere interactions are lower than for the patch–patch interaction. The melting temperatures for the polystyrene–polystyrene and polystyrene–TPM interactions are always 6–20 °C below that of the TPM–TPM interaction. Inset, illustration of DNA-coated compressed clusters: red, DNA-coated TPM patches; white, polystyrene spheres not coated with DNA. Scale bar, 5 μm.