DNA gets a new - and bigger - genetic alphabet

Hachimoji DNA could be a far more durable way to store digital data that could last for centuries

In 1985, the chemist Steven A Benner sat down with some colleagues and a notebook and sketched out a way to expand the alphabet of DNA. He has been trying to make those sketches real ever since.
 
On Thursday, Benner and a team of scientists reported success: in a paper, published in Science, they said they have in effect doubled the genetic alphabet. Natural DNA is spelled out with four different letters known as bases — A, C, G and T. Benner and his colleagues have built DNA with eight bases — four natural, and four unnatural. They named