Fig. 2

crRNA screening. A The bp26-crRNA-1–4 structure and the corresponding target sequences. The target sites are highlighted in blue, and PAM sequences are marked in red. B To determine the products of Cas12a cleavage, 20 μl of each reaction was electrophoresed (2% agarose), M: DL 500 DNA marker (Takara, Code No. 3590Q), 1–4: crRNA-1–4, (RPA amplification products were 340 bp, 261/79 for crRNA-1, 303/37 for crRNA-2, 310/30 for crRNA-3, 174/166 for crRNA-4), N: negative control. C Four groups of crRNAs were screened by the quantitative fluorescence method. The reaction was performed at 42 °C for 40 min, and the signal was collected every 1 min. The reaction entered the plateau phase at 8–10 min. As shown in the figure, the endpoint fluorescence value of crRNA-2 was slightly higher than that of crRNA-1 and crRNA-3 and significantly higher than that of crRNA-4