Fluorescent confocal image of SY5Y cells stained OCT4 (E125) antibody. SY5Y cells were fixed with 4% PFA (20 min), permeabilized with Triton X-100 (0.2%, 30 min), then incubated OCT4 (E125) primary antibody (1:500, 2 h at room temperature). For secondary antibody, Alexa Fluor 488 conjugated donkey anti-rabbit antibody (green) was used (1:1000, 1h). Cytoplasmic actin was counterstained with Alexa Fluor 555 (red) conjugated Phalloidin (5.25 mu M, 25 min). Nuclei were counterstained with Hoechst 33342 (blue) (10 ug/ml, 3 min). OCT4 immunoreactivity is localized mainly to the nuclei and also to the cytoplasm.