Co-staining of intracellular amastigotes and CK18 in infected HeLa cells. HeLa cells were left untreated (Medium, A) or transiently transfected with control RNAi (B) or CK18 RNAi (C). After 24 h, cells were infected with tissue culture trypomastigotes of the Y (A-C) strain. After 48 h, the cells were fixed, and stained for CK18 (green fluorescence), parasites (red fluorescence), and DAPI (blue). Images were obtained individually and merged. Magnification bar = 80 μM.