Abstract Genetically modified (GM) crops such as Bt11 maize have obtained biosafety certificates for cultivation across a wide geographical region, while their cultivation and use still require regulatory oversight. Therefore, the development of practical approaches to achieve effective supervision of GM crops is in great demand. Here, we propose a polymerase chain reaction (PCR) assay (termed Cas14P) employing CRISPR/Cas14a as an end-signal reporter for sensitive analysis of GM maize. Cas14a-gRNA ribonucleoprotein (Cas14a RNP) cascades the recognition of PCR amplicons via gRNA-guided hybridization, endowing the Cas14P assay with high specificity for DNA barcode authentication. The amplification of PCR and the multiple-turnover reporting of Cas14a RNP contribute to this assay having high sensitivity with a detection limit of 0.064 ng/µL DNA and 1% GM content. Moreover, the proposed assay enables clear discrimination of GM maize cultivars (Bt11) from non-GM maize ones. These results indicate that the Cas14P assay is a reliable tool for profiling GM crops.
He et al. (Tue,) studied this question.