UF reports DNA-guided CRISPR for RNA editing

The University of Florida said on May 15 that its researchers had developed a CRISPR system that uses DNA, rather than RNA, to guide Cas12 enzymes to RNA targets, a result the team reported in Nature Biotechnology. The paper describes a platform called ΨDNA and says it enables RNA targeting by Cas12 nucleases, which have traditionally relied on RNA guides. (nature.com) The work was first reported as a 2024 preprint and was formally published online on May 15, according to the university and PubMed records. (pubmed.ncbi.nlm.nih.gov) The study was led by Piyush Jain of the University of Florida, with co-authors including Carlos Orosco, Boyu Huang and Santosh R. Rananaware, according to the paper. Affiliations listed on PubMed include the University of Florida and CasNx, an Alachua, Florida-based company, and the university said the structural work was done with researchers at the University of Texas at Austin. (biorxiv.org) ### How is this different from standard CRISPR systems? Nature Biotechnology said the new system uses a DNA-based guide to direct Cas12 toward RNA, departing from the usual arrangement in which CRISPR enzymes use RNA guides. The paper says the researchers engineered ΨDNA to mimic a CRISPR RNA scaffold in reverse orientation, allowing AsCas12a and Cas12i1 to recognize RNA. (news.ufl.edu) Piyush Jain told the University of Florida that existing RNA-targeting CRISPR systems rely on RNA guides and can face stability, cost and off-target tradeoffs. The university said DNA guides are more stable and easier to produce than RNA guides, which the researchers said could broaden diagnostic and therapeutic use. (pubmed.ncbi.nlm.nih.gov) ### What did the researchers show in experiments? The PubMed abstract said ΨDNA triggered strong single-stranded DNA trans-cleavage for detection of diverse RNA species, including hepatitis C virus RNA in clinical samples. The same abstract said the system delivered 100% accurate HCV RNA detection in those samples. (nature.com) The paper also reported 70% to 95% multiplex knockdown of endogenous intracellular RNA transcripts across multiple human cell lines. In the same study, the authors said co-delivery of crRNA and ΨDNA allowed simultaneous DNA editing and RNA knockdown with a single effector. ### What does the structural work add? (news.ufl.edu) A March 19, 2026 bioRxiv preprint from University of Texas at Austin and University of Florida researchers reported the cryo-electron microscopy structure of Acidaminococcus sp. Cas12a bound to a ΨDNA guide and RNA target. The preprint said the structure was resolved at 3.18 angstroms. (pubmed.ncbi.nlm.nih.gov) The preprint said the ΨDNA hairpin bridges Cas12a’s recognition and nuclease lobes and positions the spacer to form a canonical RNA-DNA heteroduplex. The authors said those data provide a structural framework for how Cas12a can accommodate a DNA guide while recognizing an RNA substrate. (pubmed.ncbi.nlm.nih.gov) ### Where could this be used first? The University of Florida said the system could be used in diagnostics and in approaches that modulate RNA without changing the underlying DNA sequence. The paper itself reported direct RNA detection, intracellular RNA knockdown and enzyme fusions that extended the platform to RNase H-mediated RNA degradation and METTL3-based epitranscriptomic editing. (biorxiv.org) Nature Biotechnology also published a related editorial item on May 15 under the headline “Guide DNA — not RNA — expands the CRISPR toolkit,” describing the result as an expansion of the design space for CRISPR-Cas12 systems. That characterization came from the journal, not the UF paper itself. (biorxiv.org) ### What happens next? The University of Florida said the next step includes building on the platform for diagnostics and treatments, while the March 2026 structural preprint remains available on bioRxiv from Jain and David W. Taylor’s teams. The published paper lists Jain as corresponding author and shows continuing participation from University of Florida researchers and collaborators at UT Austin. (news.ufl.edu) (nature.com)