Replication of HSV-1 in the SIRC cell line. SIRC cells were infected with the KOS strain of HSV-1 at an MOI of 1 for 48 h (B). Mock-infected SIRC cells cultured in parallel were left untreated (A). HSV-1 replication was examined by confocal microscopy after staining with an HSV gD protein-specific rabbit polyclonal antibody preparation and FITC-conjugated anti-rabbit immunoglobulin. Results are representative of three independent experiments.