Figure 3

Similarity analyses of the “bath salts” and prediction of immunoassay cross-reactivity. Similarity analyses of mephedrone/methcathinone and 3,4-methylenedioxypyrovalerone (MDPV) – (A) 2D similarity of methcathinone to 287 amphetamine-like compounds. (B) 2D similarity of compounds that are cross-reactive, non-cross-reactive, or untested for the Randox Mephedrone/Methcathinone ELISA. (C) ROC curve analysis for the ability of 2D similarity to predict the cross-reactivity of compounds for the Randox Mephedrone/Methcathinone ELISA. The AUC is 0.942. Maximum efficiency of 88.9% is achieved at a cutoff of 0.455 (sensitivity = 87.5% and specificity = 89.3% at that cutoff). (D) 2D similarity of MDPV to 287 amphetamine-like compounds. (E) 2D similarity of compounds that are cross-reactive, non-cross-reactive, or untested for the Randox MDPV ELISA. (F) ROC curve analysis for the ability of 2D similarity to predict the cross-reactivity of compounds for the Randox MDPV ELISA. The AUC is 0.987. Maximum efficiency of 97.2% is achieved at a cutoff of 0.673 (sensitivity = 80.0% and specificity = 100.0% at that cutoff).