...follows: scientists would first create scaffolds of designer DNA manipulated into specific shapes. Rothemund has made DNAstructures in the shapes of circles, stars, and happy faces. A pattern would then be etched into a photo-resistant surface...
http://news.zdnet.com/2100-9595_22-6231183.html
...These instructions also include code on how it handles self-repair, reads/writes values, security (what other DNAstructures or cell structures are allowed to interact with this information or chemical load). Maybe the instructions also...
http://www.tdan.com/i026fe02.htm