Lifeboat Foundation

DNA — now with a new base pair! (credit: Romesberg Lab)

Scientists at The Scripps Research Institute (TSRI) have developed the first stable semisynthetic organism — a bacterium with two new synthetic bases (called X and Y) added to the four natural bases (A, T, C, and G) that every living organism possesses. Adding two more letters to expand the genetic alphabet can be used to make novel proteins for new therapeutics, according to the researchers.

All life as we currently know it contains just four bases that pair up to form two “base pairs” — the rungs of the DNA ladder — which are simply rearranged to create different organisms.