Fig. 3. Fluorescence of JC-1 (A,B) and TMRM (C,D) in G. dibranchiata erythrocytes exposed to sulfide (A,C; 0.11-1.9 mmol l^-1) or CCCP (B,D; 0.10 mmol l^-1) for 1 h. JC-1 fluorescence ratio and TMRM fluorescence emission at each sulfide concentration are normalized to that of control erythrocytes (erythrocytes incubated in sulfide-free buffer for 1 h). Values are means ± S.D. (N=8 for JC-1, N=4 for TMRM). CCCP (0.10 mmol l^-1) was added as a positive control for loss of m. The regression line represents a sigmoidal dose-response curve (see equation in text) with correlation coefficient, significance and EC₅₀ listed in each panel. Asterisks represent a significant effect of sulfide or CCCP compared to the control value (no toxin) by RM ANOVA (^*P<0.05, ^**P<0.01, ^***P<0.005).