Figure 4.

The principle of the clustered regularly interspaced short palindromic repeats (CRISPR)-based technique for the detection of SARS-CoV-2. CRISPR/Cas12 and CRISPR/Cas13 are used to detect the viral RNA of SARS-CoV-2. The Cas13 complex binds to the target sequences. This binding activates the general nuclease enzyme activity of Cas13 to cleave the target sequence. The RNA is then detected by a fluorescence signal. The activity of Cas12 is similar to the activity of Cas13. One difference between the two is the position of the nuclease enzyme. Adapted by permission. Copyright of Barrangou R. et al. [83].