Sera

Sera helps target-discovery biologists decide which screen hits to advance. It reconciles a CRISPRi mRNA screen against a protein screen: for each gene and condition, do the readouts agree, or does one flag a hit the other misses? On Alex Marson's genome-scale CD4+ T-cell screen, Sera ranks 7,195 candidates, then has Claude challenge its own front-runners on donor/guide robustness, real knockdown, and statistical power, and shows the rejects. Take its top corroborated hit, NFKB2: the readouts agree at 8 hours, then split by 48, when only the protein screen flags it. That late, protein-only signal is the fingerprint of noncanonical NF-κB, which acts after transcription where an mRNA screen goes blind. Sera returns one call: advance or hold, plus the experiment that settles it. The trust rule is simple: Claude reasons, but it never writes a fact. Deterministic code produces every number, identifier, and citation. Claude can only point, choosing a paper or structure by its position in a code-retrieved list, never typing a PMID or accession. It structurally cannot invent a reference. A controls-first gate also hides every novel pick until Sera first recovers the screen's known biology (5/5, both screens).