Immunocytochemistry analysis of NPM1 in A549 cells. Samples were incubated with NPM1 polyclonal antibody (Product # PA5-12447) using a dilution of 1:25 for 1 h at 37°C followed by Alexa Fluor® 488 conjugated donkey anti-rabbit antibody (green) at a dilution of 1:400 for 50 min at 37°C. Cells were fixed with 4% PFA (20 min) and permeabilized with Triton X-100 (0.1%, 10 min). Cytoplasmic actin was counterstained with Alexa Fluor® 555 (red) conjugated Phalloidin (7 units/mL, 1 h at 37°C). NPM1 immunoreactivity is localized to Nucleus and Nucleolus significantly.