FIG. 4.

Colocalization of EGF in virus-fused endosomes. DiOC18/R18-labeled virus and Cy5-labeled EGF were bound to HeLa cells for 10 min at 4°C and then incubated at 37°C for 20 min. Virus and virus-fused endosomes (left), EGF (center), and the merged image (right) are shown. Cy5-EGF is colored blue, which is a pseudocolor. The cell nucleus is indicated by N. G/R values for four fluorescent spots are indicated. The red and orange spots (G/R = 0.1 to 0.9) did not contain EGF, although the green spot (3.0) contained EGF. Yellow and green spots (*) close to the nucleus contained EGF. IFV, influenza virus. Bar = 10 μm.