Claude Designs Protein Binders Against Scorpion Toxins, Anthropic Says

Anthropic says an internal Claude research model designed new proteins that attach to scorpion neurotoxins, an early step toward possible new antivenoms. The company published the results on October 20, 2026.

Why scorpions

According to Anthropic, scorpions sting 1.2 million or more people every year, causing more than 3,250 deaths, mostly among children in places with limited access to medical care. Existing antivenoms are made from the antibodies of immunized horses, a slow and expensive process, and they usually work against only a few toxins.

What Claude did

Working from Anthropic’s prompt, developed with Citrini Research, plus four follow-ups, an internal research model operating within Claude Science ran a design campaign mainly autonomously over 64 hours. It used 12 design tools to generate 318,484 protein designs against five toxins from scorpions in Mexico, Brazil, North Africa and the Middle East, and picked 180 for testing. Anthropic’s team added 31 more with Claude’s help.

What the lab found

Two contract research labs, Adaptyv Bio and Twist Bioscience, tested all 211 designs. 17 met Anthropic’s strict criteria for a binder: seven against the toxin Cn2, four against AaH II, four against AaH I and two against LqhIII. None of the designs aimed at several toxins at once bound more than one.

The two strongest, against Cn2 from the Mexican scorpion Centruroides noxius, bound at single-digit nanomolar strength. Competition tests suggest they attach on or near the same site as LR, an antibody reported to neutralize Cn2 in mice.

The big caveat

This is not an antivenom. Anthropic says it has not tested any design for neutralization in cells or for protection in animals, and binding was measured only against lab-made toxins rather than toxin purified from venom. Those are the next steps.

Anthropic is releasing all 211 designs and their data so other researchers can build on the work.