Immunofluorescence staining of HSP40 in HEK293 cells. HEK293 cells were transfected with pVAX1-HSP40 or pVAX1. At 72 h after transfection, the cells were fixed, permeabilized, and incubated with anti-T. gondii primary antibody. The cells were then incubated with fluorescein-conjugated secondary antibody and observed under a fluorescence microscope. The experiment was repeated three times, yielding similar results. The cells transfected with pVAX1-HSP40 showed the immunofluorescence of HSP40 proteins in the cytoplasm (A), whereas the cells transfected with the empty pVAX1 plasmid displayed little cellular immunofluorescence (B). Scale bar: 10 μm.