The 'sequencing by synthesis' chemistry allows for precise and efficient cyclic sequencing, reading one base at a time across billions of DNA fragments simultaneously.

“it also allowed you to do something um uh which is called cyclic sequencing um in a very precise um and efficient and fast way where you read off one basic at a time um and you can control it and so you imagine you have say a lawn of a billion DNA fragments and you're on base three on every single fragment and you want to know what base four is on every fragment it allowed you to simultaneously sequence just one more base on all billion fragments read it out across your whole lawn and then um once you read it out add one more base read it all out”

“it allowed you to to miniaturize um the sequencing reactions um so you could have a huge number ultimately billions and in a very small glass slide”