Uptake of diamidines by T. b. brucei strain s427. Trypanosomes isolated from infected female Wistar rats were immediately exposed to 10 μM permeant in complete HMI-9 media for up to 1 h at RT. Intracellular diamidine concentrations were measured using a fluorescence-based assay. The data are representative of the results of at least three similar experiments, each performed in at least triplicate. ○, DB75; ■, DB820; ▴, CPD0801. Bars represent standard errors of the means (SEM) of quadruplicate determinations of this particular experiment. When not shown, error bars fall within the symbol.