Escherichia coli, or E. coli, is one of the most common model organisms used in biology. They grow quickly, are well characterized, and in recent years have been genetically modified and engineered to respond to specific chemical signals. In this image, you can see colonies of E. coli suspended within a solid hydrogel. These cells have been engineered to split, or cleave, a chemical called X-gal in response to an inducer signal. As they receive the signal over time and space, the cells begin to cleave the X-gal, creating this brilliant blue color, reminiscent of indigo.

This image is exciting because it is an artifact of a unique process pioneered by our lab. We combined the latest high resolution 3D printing techniques with the advantages of biological engineering to create a hybrid object.