Fig. 1

The CRISPR/CAST package detection principle. Figure 1 shows the detection principle for the CRISPR/CAST package, and the detection process is divided into three steps. In the first step, the RPA isothermal amplification technology is used to amplify the Brucella target DNA. In the second step, 3 μl RPA amplification products are added to the reaction solution containing Cas12a, crRNA and the ssDNA with fluorescent report group at 42 °C for 10 min. The third step is to dilute the second reaction solution with pure water to 50 μl and then insert the test strip into the solution. After the test strip is thoroughly infiltrated, the result can be observed within 10 min with the naked eye. If the detection line color is present, the result is positive. The result is negative if the detection line shows no color and the quality control line is present. The result is invalid if the quality control and detection line color are present