It's rare for a month to go by without some aspect of DNA
sequencing making the headlines. Species after species has seen
its genome completed, and the human genome, whether it's from
healthy individuals or cancer cells, has received special
attention. A dozen or more companies are attempting to bring new
sequencing technology to market that could eventually drop the
cost of sequencing down to the neighborhood of a new laptop.
Arguably, it's one of the hottest high-tech fields on the
planet. But, although these methods can differ, sometimes
radically, in how they obtain the sequence of DNA, they're all
fundamentally constrained by the chemistry of DNA itself, which
is remarkably simple: a long chain of alternating sugars and
phosphates, with each sugar linked to one of four bases. Because
the chemistry of DNA is so simple, the process of sequencing it
is straightforward enough that anyone with a basic understanding
of biology can probably understand the fundamentals. The new
sequencing hardware may be very co