In 1953, when scientists conclusively identified DNA’s structure, it was a monumental, Nobel-Prize-winning revelation: four nucleotides, each containing a letter-labeled base, were arranged in a double helix structure. These four bases, or “letters,” form pairs: adenine, A, matches with thymine, T, and cytosine, C, bonds with guanine, G. These pairs are essentially the building blocks of life on Earth; the way in which the pairs are arranged creates the genetic instructions for how proteins are made, which in turn aid in pretty much every critical process that keeps us alive.
Now, an interdisciplinary team of researchers has expanded the genetic alphabet by creating synthetic DNA that uses eight letters rather than four, according to a new study published in the journal Science. The new manufactured structure is called "hachimoji DNA," from the Japanese words for "eight" and letter." Creating hachimoji DNA was, as Carl Zimmer writes in The New York Times, “a chemical tour-de-force” for the group led by Steven Benner, a synthetic biologist at the Foundation for Applied Molecular Evolution. The advance offers new possibilities in many fields, including medical research and data storage.