I’m Helena de Puig, CEO and co-founder of Externa. We spun out of the labs of George Church and Jim Collins. I have a PhD from MIT and did my postdoc at Harvard.

At Externa, we’re expanding the chemical alphabet of life by enabling programmable genetic code expansion — without host cell engineering. Our platform allows us to incorporate 100+ non-standard amino acids into proteins of any size, including multiple distinct nsAAs (3+) or repeated insertions (16×) within a single protein, across peptides, AI-designed miniproteins, nanobodies, and full-length IgGs.