Laboratory tests for the accurate and rapid identification of SARS-CoV-2 variants can potentially guide the treatment of COVID-19 patients and inform infection control and public health surveillance efforts. Here, we present the development and validation of a rapid COVID-19 variant DETECTR assay incorporating loop-mediated isothermal amplification (LAMP) followed by CRISPR-Cas12 based identification of single nucleotide polymorphism (SNP) mutations in the SARS-CoV-2 spike (S) gene.

Laboratory tests for the accurate and rapid identification of SARS-CoV-2 variants have the potential to guide the treatment of COVID-19 patients and inform infection control and public health surveillance efforts. Here we present the development and validation of a COVID-19 variant DETECTR® assay incorporating loop-mediated isothermal amplification (LAMP) followed by CRISPR-Cas12 based identification of single nucleotide polymorphism (SNP) mutations in the SARS-CoV-2 spike (S) gene. This assay targets the L452R, E484K, and N501Y mutations associated with nearly all circulating viral lineages. In a comparison of three different Cas12 enzymes, only the newly identified enzyme CasDx1 was able to accurately identify all three targeted SNP mutations. We developed a data analysis pipeline for CRISPR-based SNP identification using the assay from 91 clinical samples (Ct < 30), yielding an overall SNP concordance and agreement with SARS-CoV-2 lineage classification of 100% compared to viral whole-genome sequencing. These findings highlight the potential utility of CRISPR-based mutation detection for clinical and public health diagnostics.

The programmable nature of sequence-specific targeting by CRISPR-Cas nucleases has revolutionized a wide range of genomic applications and is now emerging as a method for nucleic acid detection. We explore how the diversity of CRISPR systems and their fundamental mechanisms have given rise to a wave of new methods for target recognition and readout. These cross-disciplinary advances found at the intersection of CRISPR biology and engineering have led to the ability to rapidly generate solutions for emerging global challenges like the COVID-19 pandemic. We further discuss the advances and potential for CRISPR-based detection to have an impact across a continuum of diagnostic applications.