Ars Technica: To better study biological networks, such as gene expression, which is essential to the development of living things, researchers have constructed a biochip containing an array of artificial cells. The cells are composed of bundles of DNA assembled on the surface of circular silicon compartments. The DNA was fed nutrients through thin capillaries, which allowed the genes to metabolize. To monitor how that complex process evolves as the cell develops and reacts to environmental changes, the researchers tracked the presence of green fluorescent protein expressed from the DNA. With the biochip, they were able to successfully demonstrate gene expression at the embryonic scale.