Scientists are expanding the genetic code of life, using man-made DNA to create a semi-synthetic strain of bacteria — and new research shows those altered microbes actually worked to produce proteins unlike those found in nature. It’s a step toward designer drug development. One of the first lessons in high school biology: All life is made up of four DNA building blocks known by the letters A, T, C and G. Paired

together, they form DNA’s ladder-like rungs. Now there’s a new rung on that ladder. A team at The Scripps Research Institute in La Jolla, California, expanded the genetic alphabet, creating two artificial DNA “letters” called X and Y. A few years ago, the researchers brewed up a type of E. coli bacteria commonly used for lab research that contained both natural DNA and this new artificial base pair — storing extra genetic information inside cells.  READ MORE