Karen from Instructables sez, "Instructables author Patrik has rigged up a homemade bioprinter, a 3D printer that 'prints' in biological material. Check out his amazing project. This is one of the many creative entries we've seen come in for our SciStarter Citizen Science Contest, where we are challenging our users to create solutions for real scientific problems."
As our first real "bioprinting" experiment, we wanted to start with something simple, instead of jumping straight into printing with live cells. We decided to print with a solution of arabinose onto filter paper. Then we cut out the filter paper, and put it onto an agarose plate on which we had grown a lawn of E. coli that we had engineered to carry the pGLO plasmid. This plasmid carries the Green Fluorescent Protein (GFP), under control of an arabinose-sensitive promoter. (Stay tuned for an instructable on how to make your own GFP-expressing E. coli).
As a result, wherever we had printed arabinose on the filter paper, we now saw the E. coli light up green under UV light! Note that the beauty of this experiment lies in its simplicity: we only had to print with a simple sugar solution, rather than with bulky live cells; and we were printing on paper, so we didn't even have to change the paper handling machinery. You could also try printing with antibiotics, or even proteins, such as enzymes or growth factors.
The second-to-last image above shows our first test print, where we has printed arabinose over half of the filter paper - and half of the plate lights up under UV light. In the second image, we had printed the BioCurious "eyeball" logo. Success! Unfortunately the sharpness of the image definitely leaves much to be desired. Presumably, the arabinose tends to diffuse through the filter paper, which smears out the printed pattern. We should be able to do much better by printing directly on the agarose.