DNA to Z

Scientists have created bacteria that thrive using an expanded "genetic alphabet". The blueprint for all life forms on Earth is written in a code consisting of four "letters": A, T, C and G, which pair up in the DNA double helix. But the lab organism has been modified to use an additional two, giving it a genetic code of six letters. Jeff and Anthony try to figure out why they are doing this, and discuss what this might mean for the future.