Nucleic acid detection via protein readout through Cas-controlled gating of cell-free protein synthesis

We present a modular platform that converts CRISPR target recognition into programmable protein outputs for nucleic acid detection. This system couples Cas-mediated collateral cleavage with cell-free protein synthesis. In the presence of a target, Cas-mediated collateral cleavage releases an extension-competent trigger DNA that gates reporter expression. Although collateral cleavage is inherently indiscriminate, we achieve deterministic fragment generation by employing chemically programmed precursors bearing backbone modifications-exemplified here by phosphorothioate linkages-that constrain cleavage to predefined sites. Using Bacillus anthracis and E. coli O157:H7 as a model, the developed CRIVER assay enables concurrent readouts of 16S rRNA together with the species-specific capB or ecf1 loci by integrating Cas13a-mediated RNA recognition and Cas12a-mediated DNA recognition into a dual-channel workflow. Taken together, proposed method establishes addressable signaling at the protein layer, supports protein-based outputs in a modular workflow, and provides a general route to sensitive, dual-channel nucleic acid detection.