Hematoxylin/eosin (A-B and G) and fluorescent staining (C-F, H) of EpiGingival tissues. The tissues were either mock infected (A, C) or infected with 2 × 104 PFU of HCMV mutant ΔUS18 (G and H) and the parental TowneBAC (B, D, E, and F), harvested at 7 days post infection, fixed with Streck Tissue Fixative, frozen in 2-methylbutane submerged in liquid nitrogen, and cross-sectioned at 9 μm using a LEICA cryostat LC1900 sectioner, stained with either hematoxylin/eosin or DAPI, and visualized (magnification, ×400). The cells that were infected with TowneBAC and ΔUS18, which carried a GFP expression cassette, were visualized by detecting the expression of GFP (C, E, F, and H). The images of the DAPI-staining tissues (DAPI) (D) and the infected cells that expressed the GFP (GFP) (E) were used to generate the composite image (GFP+DAPI) (F). Similar composite images (GFP+DAPI) are shown in (C) and (H).