Fig. 3
From: Design of a chimaeric antigen and its use in the detection of IgG antibodies against rubella virus
ROC curve of 94 cord blood was detected by P6 indirect ELISA. The optimum critical value was determined by the Yoden index (Yoden index = sensitivity + specificity − 1). Sensitivity = [true positive cases/(true positive cases + false negative cases)] × 100%. Specificity = [true negative cases/(true negative cases + false positive cases)] × 100%. The optimal critical value was 0.317. According to the critical value, the coincidence rate, specificity and sensitivity of the ELISA were 86.2%, 88.89%m 84.48% respectively