Imre was a master of the microscope and immunostaining techniques. See the gallery of his microscopy art - a fluorescent confocal image of the Oct4 transcription factor. Oct4 is expressed in totipotent embryonic stem and germ cells. In this example, SY5Y cells were fixed with 4% PFA (20 min), permeabilized with Triton X-100 (0.2%, 30 min), then incubated with AP2046c 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 μM, 25 min). Nuclei were counterstained with Hoechst 33342 (blue) (10 µg/ml, 3 min). Oct4 immunoreactivity is localized mainly to the nuclei and also to the cytoplasm.