*2.6. Determination of the Murine Cytomegalovirus (MCMV) Growth Curve in Host Cells*

NIH3T3 cells (1.00 <sup>×</sup> 105 cells/well) were plated in a 12-well format containing 1 mL of growth medium and infected with MCMV (multiplicity of infection, MOI = 0.05) 1 day later (initial titer: 5.00 <sup>×</sup> 103 pfu/mL). In the preliminary test, the viral titers were 4.20 <sup>×</sup> 103, 1.40 <sup>×</sup> 105, 5.10 <sup>×</sup> 105, 2.70 <sup>×</sup> 10<sup>5</sup> pfu/mL at 1, 3, 5 and 7 days post infection, respectively. We found that the viral titers were increasing for 1 to 5 days post infection, but gradually decreasing after 5 days. The results demonstrated that MCMV reached the highest titer at the 5th day post infection.
