One of the first things you learn in Biology 101 is that the genetic code consists of four letters: A, T, C, and G. Each represents a chemical building block of DNA, the molecule that encodes the information necessary to build life as we know it. But what if we didn’t have to settle for just four letters? Now, scientists have accomplished something once thought impossible: They’ve created cells with an expanded genetic alphabet that includes two more letters.
Having more letters to work with potentially opens the door to a huge range of novel molecules. (A rough analogy: Just think how many crazy new words you could spell with 39 letters instead of the usual 26). With further refinements, synthetic cells might one day be used to create–or evolve–proteins that don’t exist in nature, as well as new sequences of DNA and RNA, any of which could be useful for research, diagnosing disease, or creating new therapies. But that’s still a ways off. Learn more here.