In a way, sequencing DNA is very simple: There's a molecule, you look at it, and you write down what you find. You'd think it would be easy—and, for any one letter in the sequence, it is. The problem ...

Add Yahoo as a preferred source to see more of our stories on Google. FILE PHOTO: A sign at the front entrance to the global headquarters of Illumina is pictured in San Diego, California (Reuters) - ...