S. mansoni miracidia were obtained by hatching of schistosome eggs as previously described. The resulting miracidial suspension was collected, washed with Chernin's balanced salt solution (CBSS) and enumerated prior to being used for ex vivo miracidia to sporocyst screens as previously reported. Each compound was tested at 0.5, 2.0, 5.0, 10 and 25 µM final concentrations (in 1% DMSO). Each treatment was set up in duplicate (15-25 miracidia/well). Each titration was performed in three independent experiments (two technical replicates per data point).