Fig 3. Flow cytometry analysis of transferrin-AlexaFluor 633 endocytosis by amastigotes and epimastigotes of Trypanosoma cruzi.

(A) Flow cytometry histograms of parasites incubated with transferrin at different temperatures, and then treated with acetic acid, or left untreated. Epimastigotes were used as positive control, and negative control parasites (black) were incubated in medium without labeled transferrin. These data show that isolated intracellular amastigotes internalize transferrin at 37°C. (B) Normalized medians (stained/unstained control) of the fluorescence peaks. Note the low endocytosis levels in axenic amastigotes (N = 3). ***p<0.001. a, acetic acid treatment.