CRISPR-Assisted DNA Detection, a novel dCas9-based DNA detection technique

Abstract

Nucleic acid detection techniques are always critical to diagnosis, especially in the background of the present COVID-19 pandemic. The simple and rapid detection techniques with high sensitivity and specificity are always urgently needed. However, the current nucleic acid detection techniques are still limited the traditional amplification and hybridization. To overcome the limitation, we here develop a CRISPR/Cas9-assisted DNA detection (CADD). In this detection, DNA sample is incubated with a pair of capture sgRNAs (sgRNAa and sgRNAb) specific to a target DNA, dCas9, a signal readout-related probe, and an oligo-coated solid support beads or microplate at room temperature for 15 min. During this incubation, the dCas9-sgRNA-DNA complex is formed and captured on solid support by the capture sequence of sgRNAa and the signal readout-related probe is captured by the capture sequence of sgRNAb. Finally the detection result is reported by a fluorescent or colorimetric signal readout. This detection was verified by detecting DNA of bacteria, cancer cell and virus. Especially, by designing a set of sgRNAs specific to 15 high-risk human papillomaviruses (HPVs), the HPV infection in 64 clinical cervical samples were successfully detected by the method. All detections can be finished in 30 minutes at room temperature. This detection holds promise for rapid on-the-spot detection or point-of-care testing (POCT).