They're using pre-built materials already available.
I'm holdin' out for when they are able to make the pre-built materials, but my suspicion is that will be too complex, and a certain Grand Designer may have implemented steps that will forever preclude us from doing that.
Aw, the hubris! Man is an arrogant little creature!
Sauron
>> I’m holdin’ out for when they are able to make the pre-built materials...
I think the endeavor starts from false principles, but still could lead to a better understanding of biological systems, so I encourage the experiment. We still know very little about how life works and this project is attempting to do more than we really understand—hoping to learn the details along the way. It will be interesting to see if the assumptions are proven false, but I doubt such a result will be acknowledged in favor of putting some spin on the results to appear as if they have made some progress and are hopeful for the future.
What if there are specific structural requirements for life that have no natural chemical path? What if the minimal life form is discovered to be nearly as complex as modern bacteria? What if the combinations of possible workable DNA sequences is severely limited to the point that only species known to have existed are capable of existing? I don’t think scientists are prepared for these scenarios.