The following is a major development I simply want to pass on to others that may not have seen it:
Scientists Add Letters to DNA's Alphabet, Raising Hope and Fear
By ANDREW POLLACKMAY 7, 2014
DNA 2.0. By adding a new base pair, X and Y, to DNA's A-T and G-C pairs, researchers will enable organisms to build proteins from as many as 172 different amino acids.
...the newly expanded genetic code opens the door for synthetic biologists to create microbes capable of building their proteins out of as many as 172 different amino acids, both natural and artificial-a potential boon to drug and materials developers.