Comment by yashgaroth

Is there a reason why this specifically has to happen in living cells? I get that you can skip the hassle of DNA delivery, but it makes the entire thing about 1,000x more difficult - which seems to offset the posited benefits.

Not to mention that the requirements in the solicitation for speed, accuracy, and length of product are each at least an order of magnitude above what is possible in current in vitro oligo synthesis. And that's just for the intermediate, 19-month goal, much less the later ones.

Certainly, DNA synthesis has been a limiting factor in bio R&D and both the cost and turnaround time have remained fairly stagnant, especially for gene-length products and given the near-term explosion in demand from AI-designed proteins.

I can appreciate that DARPA is a fan of moonshots but would it be advisable to break this into sub-projects such as generally improving DNA+gene synthesis, developing new methods for cell transfection, error correction, in vivo assembly, etc? Focusing on in vivo and light-directed only (and together) might not be the best path forward, though it certainly sounds sci-fi.