Fig 2.

Assay characterization. (A) Frequency distribution of intracellular amastigote count. At the end of the intracellular Leishmania assay, the number of amastigotes in 19,738 infected cells was counted using the automated image analysis algorithm, and a frequency distribution was plotted. (B) Growth curve for intracellular amastigotes. Cells were plated and infected in 384-well plates, and one plate was fixed at each time point. The values represent the number of amastigotes per infected cell (i.e., the averages and standard deviations from the entire plate). A linear regression was calculated (R² = 0.93). (C) Growth curve for axenic amastigotes in 384-well plates. Axenic amastigotes were counted at the indicated time points. The y axis shows the number of amastigotes per ml (×1,000). An exponential curve was fitted to time points 0 to 55 h (R² = 0.999). The results from triplicate experiments are shown. (D) Replicate potencies. The potency of 85 compounds was tested on two separate occasions in the intracellular Leishmania assay, and the potencies of the replicates were plotted against each other. A linear regression was calculated (R² = 0.88).