Qualitative and Quantitative Detection of CRISPR-Associated Cas Gene in Gene-Edited Foods.

Effective regulation of gene-edited products and resolution of public concerns are the prerequisites for the industrialization of gene-edited crops and their derived foods. CRISPR-associated protein, the core element of the CRISPR system, requires to be regulated. Thus, there is an urgent need to establish qualitative and quantitative detection methods for the gene. In the present study, the primers and probes were designed and screened for (), which is the most commonly used target site in gene editing; we performed PCR system optimization, determined the optimal primer concentration and annealing temperature, and established qualitative PCR and quantitative PCR (qPCR) assays for detecting in gene editing by specificity and sensitivity tests. In specificity testing, qualitative PCR and qPCR methods could 100% detect samples containing DNA, while the detection rate of other samples without was 0%. In the assay sensitivity test, the limit of detection of qualitative PCR was 0.1% (approximately 44 copies), and the limit of detection of the qPCR method was 14 copies. In the stability test, both the qualitative PCR and qPCR methods were repeated 60 times at their corresponding lowest detection limit concentrations, and the results were positive. Thus, the qualitative and quantitative assays for are specific, sensitive, and stable. The method provides technical support for the effective monitoring of gene-edited products and their derived foods in the future.