A multidisciplinary team of researchers has created tiny DNA boxes measuring just 30 nanometers on each side. The boxes, which can be unlocked with a gene “key,” could be used for drug delivery or as sensors.

The “DNA origami” boxes use oligonucleotides, short snippets of nucleic acid bearing genetic information, to fold longer strands of DNA into a complex structure. Each box is large enough to hold a single ribosome, the cell’s machine for making proteins.