The change in the intracellular distribution of mutated NS1 protein. Vero cells were infected with NS1F, NS1F-ELCmut, or mock infected and were fixed at 15 (mock fixed at 15 h alone), 24, 32 and 48 h p.i. NS1 (white arrows) was detected by dual labelling using anti-FLAG (green) and anti-NS1/2 (red) antibodies. Nuclei were stained with DAPI and overlay images generated using Photoshop. Representative of 3 separate experiments.