Fig. 2From: Development and comparative validation of genomic-driven PCR-based assays to detect Xanthomonas citri pv. citri in citrus plantsDetermining the Ct cut-off according to the Youden index J. The optimal cut-off point is the PCR cycle with the highest value of the Youden index value, which represents a trade-off between sensitivity and specificity. The Ct cut-off was estimated to be 35.4Back to article page