in silico

In silico means running an experiment inside a computer screen instead of using real cells or test tubes. The term comes from Latin for "within silicon" (the material computer chips are made of) — like using a recipe app to calculate taste and temperature before you actually buy ingredients and turn on the stove. If it fails, no ingredients are wasted and no time is lost, so you can try many more times, faster and cheaper.

But just because something looks plausible inside a computer doesn't guarantee it will actually work in reality. Just as a recipe app predicting a dish will taste good doesn't mean you can be sure until you actually cook and eat it, designs created in silico must eventually be checked again in a lab with real materials.

In the article, the process where Claude received only target protein information and spent 24 hours generating candidate proteins and predicting their folding structures is exactly in silico work. Real labs — Adaptyv Bio and GenScript — then synthesized the designs selected inside the computer and tested whether they actually bound. Not every design that looked promising in silico actually worked; only about half succeeded at binding. Contrary to the misconception that "the computer picked it, so a new drug is coming soon," this case shows that in silico results only become meaningful after passing lab verification.