Relationship between fluorescence signal and number of schistosomula (25–250 schistosomula per well) in the resazurin based assay. Figure shows an average curve of four replicates, bars indicate standard deviations of the performed experiments. Fluorescence was measured after 24 hours of incubation. The fluorescence decreased with schistosomula concentrations above 200 per well. Linear regression is shown for data of 25-200 NTS.