Scientists have tried to re-create the effect in plants before: In the 1980s, researchers added a firefly's luciferase gene into tobacco plant cells. (discovermagazine.com)
Akin designed the living microbots to release their DNA packages inside mammalian cells, where the pH is low (acidic) enough to dissolve the chemical bonds gluing the luciferase gene to the bacteria. (scientificamerican.com)
Akin attached a luciferase gene — which codes for the enzyme that makes fireflies glow — to L. monocytogenes and injected the germs into living mice. (scientificamerican.com)