How Does DNA Sequencing Work?

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 with DNA sequencing isn't checking the chemical identity of each link in the chain of a DNA molecule; it's checking those identities tens of millions of times without making mistakes.

The nature of DNA is such that, in many cases, if you've only got 95% of the correct sequence, you might as well have nothing at all. So, how do scientists actually read the blueprints of biology and, with them, build a large proportion of modern medicine and biotech?

Who 'Discovered' DNA Sequencing?

More or less, it all started with a guy named Frederick Sanger. Sanger created an ingenious method that allowed a person to ...