The idea is to use the 4 chemical constituents of DNA — named A, T, C and G — to put together a synthetic genome
. Then they would put that synthetic genome
into a cell, and have it direct the cell as it grew and multiplied. Now they've succeeded.
Venter says there were two enormous hurdles to accomplishing his goals. First, he needed to figure out how to make a very big piece of DNA. Most chemical synthesis techniques stop working when you get to a few thousand of DNA letters.