Bacteria that lives in the human intestines has been modified to use a 22-amino acid genetic code rather than the normal 20.

The feat, by researchers at The Scripps Research Institute and its Skaggs Institute in La Jolla, California, could provide a powerful new tool for studying problems in biophysics and cell biology.

“We have demonstrated the simultaneous incorporation of two unnatural amino acids,” says Scripps researcher Peter Schultz. “Now that we know the genetic code is amenable to expansion to 22 amino acids, the next question is, how far can we take it?”

More here.