BZLF1 transcript expression in P3HR-1 cells. BZLF1 transcript was chemically induced with PMA/ionomycin (1 μg/ml) as a positive control for EBV reactivation. Qualitative real-time PCR was performed to show positive expression of the BZLF1 transcript. Unstimulated cells served as a negative control (A). Real-time PCR amplification of the BZLF1 transcript was performed using 5 μl of cDNA from the RT reactions among P3HR-1 cells superinfected with CMV (B). Time points are indicated in both (A) and (B).