Subcellular localization of terminase subunits expressed by plasmid transfection. HEK-293 T cells were transfected with expression vectors encoding each terminase subunit fused to N-terminal FLAG (UL51), V5 (UL56), or MYC (UL89) epitope tags. 72 h post transfection the cells were fixed and stained with monoclonal antibodies specific to each epitope tag. The anti-V5 antibody was directly conjugated to FITC, whereas unconjugated primary antibodies for FLAG and MYC were detected using a FITC-conjugated anti-mouse IgG secondary antibody. Cells were counter stained with DAPI to detect nuclei. Paired images are representative micrographs taken at 0.7x (top) or 2x (bottom) zoom. In each column, cells were stained to detect the protein indicated above the column, while the expression vectors that were transfected are indicated to the left of each image pair. The percentages of cells with nuclear staining (in white) were determined by counting >50 fluorescent cells per group.