Guest guest Posted November 25, 2005 Report Share Posted November 25, 2005 18:32 23 November 2005 NewScientist.com news service Paul Marks The researchers used the living film to create an image of the " `flying spaghetti monster " , which features in an online satirical critique of the intention of the Kansas school board to teach intelligent design in schools (Image: Chris Voight)Related Articles Biggest space camera will map Milky Way 13 June 2005 Printing press spells out bugs' behaviour 30 May 2005 Forget takeout, eat a print-out 12 February 2005 Search New Scientist Contact us Web Links Chris Voigt, University of California in San Francisco Nature A dense bed of light-sensitive bacteria has been developed as a unique kind of photographic film. Although it takes 4 hours to take a picture and only works in red light, it also delivers extremely high resolution. The " living camera " uses light to switch on genes in a genetically modified bacterium that then cause an image-recording chemical to darken. The bacteria are tiny, allowing the sensor to deliver a resolution of 100 megapixels per square inch. To make their novel biosensor, Chris Voigt's team at the University of California in San Francisco, US, chose E. Coli, the food-poisoning gut bacterium. One of the reasons for that choice is that E. Coli does not normally use light - photosynthesising bacteria could have used light to prompt other, unwanted, biological processes. The researchers used genetic engineering techniques to shuttle genes from photosynthesising blue-green algae into the cell membrane of the E. coli. One gene codes for a protein that reacts to red light. Once activated, that protein acts to shut down the action of a second gene. This switch-off turns an added indicator solution black. As a result, a monochrome image could be permanently " printed " on a dense bed of the modified E. Coli. Nano-factories The living camera will never be available in the shops: Voigt's team saw it as an exercise in advanced genetic engineering. But their success in getting an array of bacteria to respond to light could lead to the development of " nano-factories " in which minuscule amounts of substances are produced at locations precisely defined by light beams. For instance, the gene switch need not activate a pigment, says Voigt. A different introduced gene could produce polymer-like proteins, or even precipitate a metal. " This way, the bacteria could weave a complex material, " he says. The UCSF team are now working on expanding the colour range of their sensor, perhaps using retinol, a substance which helps the human retina to sense a wide range of colours. As a method of nano-manufacturing, the biocamera is an " extremely exciting advance " says Harry Kroto, the Nobel prize-winning discoverer of buckminsterfullerene, or buckyballs. " I have always thought that the first major nanotechnology advances would involve some sort of chemical modification of biology. " Journal references: Nature (vol 438, p 441) Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You are posting as a guest. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.