FIG. 3.

Growth characteristics and relative particle-to-PFU ratios of wild-type (wt) and pp28-deficient viruses. (A) Production of infectious progeny in cultures of pp28-expressing fibroblasts (HFFpp28-8x) or normal fibroblasts (HFF). Cells were infected with BADwt (•), BADrevUL99 (▪), BADsubUL99 (□), or BADpmUL99 (▵) at a multiplicity of infection of 0.01 PFU/cell. Cells were lysed in culture medium at the indicated times after infection, and virus was quantified by plaque assay on HFFpp28-8x cells. (B) Relative amounts of DNA in BADsubUL99 compared to BADwt virions. DNA was prepared from a quantity of virus stock containing 10³ PFU, and aliquots of undiluted DNA and diluted (1:25) DNA were quantified by real-time PCR with a primer pair that amplified a segment of the HCMV UL10 gene. Relative fluorescence units (RFU) are plotted as a function of cycle number.