HTS assay validation.
A) Linear correlation between relative fluorescence unit (RFU) readings from resazurin reduction (y-axis) and parasite number from microscopy counting (x-axis). B) Dose response curve and EC50 (black line for L. major and grey dashed line for L. donovani) of the reference compounds used as controls: EtBr, amphotericin B, miltefosine and paromomycin. C) Distribution of 33 control microplates showing 1% DMSO as the negative control (blue dots), EtBr EC50-30 nM (black dots) and EtBr EC100-10 µM as positive controls (yellow dots) and the Z-factor of 0.62. D) Distribution plot of the duplicate assay screen of 4,000 compounds (red dots) and controls in three different concentrations, following the same color standards as in C.