Immunofluorescence staining of Hela cells. Cells were fixed with 4% PFA (20 min), permeabilized with Triton X-100 (0.1%, 10 min), then incubated for 1hr at 37°C with P9109-29B (1:25). Alexa Fluor® 488 conjugated donkey anti-rabbit antibody (green) was used (1:400, 50 min at 37°C) as secondary antibody. Cytoplasmic actin was counterstained with Alexa Fluor® 555 (red) conjugated Phalloidin (7units/ml, 1 h at 37°C). PTPN11 immunoreactivity is significantly localized to nucleolus and cytoplasm and is weakly localized to the nucleus.