Key Takeaways
Anthropic said September 23 that Claude agents, working with only a starting prompt from scientists, found a previously unrecognized enzyme system in viruses that infect bacteria.
The system, which Anthropic calls array-associated reverse transcriptases (ART), sits next to a CRISPR-like array of repeating DNA. What it does is still unknown.
About 950 Claude agents searched for 21 hours, gathered more than 200,000 enzymes and narrowed them to 20 top candidates, work Anthropic says can take experts weeks to months.
Anthropic says its Claude AI models have spotted a biological system that researchers appear to have overlooked. In early results published September 23, the company introduced a new life sciences research lab and said Claude agents spotted an enzyme system with features reminiscent of CRISPR, the bacterial system that became the basis for gene editing medicines.
What Claude found
The discovery centers on a reverse transcriptase, an enzyme that copies RNA into DNA. The enzyme itself had been identified before in a large bacteriophage, a virus that infects bacteria. What Claude appears to have noticed first is what sits beside it: a partner protein of unknown function and a long array of evenly spaced repeating DNA sequences, a layout that resembles a CRISPR array. Anthropic named the system array-associated reverse transcriptases, or ART. Early lab tests show the array is expressed as a set of distinct short RNAs, which hints it could work in a programmable way, though its actual function is not yet known.
How the search worked
Scientists gave Claude one prompt to search a large DNA database for new reverse transcriptases, then handled the lab work. Roughly 950 agents ran for 21 hours and used 210 million tokens, gathering more than 200,000 enzymes, flagging 3,500 candidate systems and narrowing them to 20 written reports for human review. All lab experiments were done by human scientists in low biosafety settings. The findings are in a preprint that has not been peer reviewed.
"This is an exciting example of how AI agents can contribute to biological discovery," said Feng Zhang, a CRISPR pioneer at MIT and the Broad Institute who reviewed the preprint.
None of this is new in one sense. Restriction enzymes, PCR and CRISPR all started with someone noticing something odd in nature. What's new is who is doing the noticing. It follows WYDE's report that Claude wrote the first computer-checked proof of Fermat's Last Theorem, and it lands alongside the Gates Foundation's $1 billion push to put AI to work in health care. Worth watching what ART turns out to do.
People Also Ask
What did Claude discover?
Claude agents identified a previously uncharacterized enzyme system in bacteriophages, called array-associated reverse transcriptases (ART), made of a reverse transcriptase, a partner protein and a CRISPR-like array of DNA repeats.
Is the ART enzyme system like CRISPR?
Its repeat array resembles a CRISPR array and is expressed as distinct short RNAs, but Anthropic says its function is still unknown and more experiments are underway.
How did Claude find the enzyme system?
About 950 Claude agents searched a DNA database for 21 hours from a single prompt, gathered over 200,000 reverse transcriptases and narrowed them to 20 candidates for human review.
Has the Claude enzyme discovery been peer reviewed?
Not yet. Anthropic released the findings as a preprint on September 23, 2026, and human scientists performed all of the lab work.