Fig. 1. Intracellular localization of EGFP and EGFP–NLS molecules in uninfected and poliovirus-infected cells. (A) HeLa cells stably expressing EGFP were mock infected or infected with poliovirus as indicated. Cells were processed and examined by fluorescent microscopy at 4.5 h after infection. EGFP fluorescence was visualized using a FITC filter. DNA: Hoechst 33258-stained nuclei were examined with a UV filter. Merged: shows the FITC and Hoechst images merged. (B) HeLa cells stably expressing EGFP–NLS fusion proteins were examined as described in (A). (C) Immunoblot analysis of EGFP–NLS- and EGFP-expressing cell lines. Whole-cell lysates were prepared after 4.5 h of infection from either mock- or poliovirus-infected cells. EGFP was detected by immunoblotting using a polyclonal antibody to GFP (Clontech).