Researchers in San Diego have added a new set of letters to the genetic code, as outlined in a paper published in Nature, allowing organisms to make proteins never before created by life on Earth. The results of their work, the researchers write, “should serve as a platform for the creation of new life forms and function.”

The building blocks of DNA consist of a four-letter alphabet soup of “A,” “T,” “G” and “C.” Those letters correspond to Adenine, Thymine, Guanine and Cytosine, the four chemicals that pair with one another and create the instruction manual for living things we know as DNA. The code for all life on earth from rats to Rachael Ray is written in the arrangement of these letters. DNA is ‘read’ into RNA, which are in turn read into proteins.