Uptake of diamidines by trypanosomes cultured in vitro. Trypanosomes of strains 427 (■), tbat1−/− (○), and B48 (▴) were exposed to 7.5 μM DB75 (a), DB820 (b), or CPD0801 (c) in complete HMI-9 media under standard culture conditions, and intracellular diamidine concentrations were measured after 1, 4, 8, and 24 h of exposure. The data are representative of the results of at least three similar experiments, each performed in at least triplicate. Bars represent SEM.