Print your own DNA
This time about DNA and the double helix. http://www.bitsfrombytes.com/wiki/index.php?title=Science_-_DNA
This resource is heavily based on the work by "Cathalgarvey" on Thingiverse... my thanks to him for producing the .stl files (and to Bogdan for spotting them and realising it would make a good T&L resource)
Dave
