Fig. 2.

(A) Procedures for constructing deletion and rescued mutants. Detailed procedures are described in Materials and Methods and Supporting Materials and Methods. (B) Multiple-step growth [multiplicity of infection (moi) = 0.05] of HCMV mutants in HFF. Cells were infected with each virus and at different time points postinfection, and cells and culture media were harvested and sonicated. The viral titers were determined by plaque assays on HFF (13). The values of the viral titer represent the average obtained from triplicate experiments. The standard deviation is indicated by the error bars.