Virus replication was also examined quantitatively by Q-RT-PCR using the virus SH gene as a target sequence [13] , [ Figure 1C ]. PVM replication was readily detected in inoculated RAW 264.7 cells, reaching ~4 × 10 5 copies per microgram total RNA on day 5 of infection. No copies of the virus SH gene were detected in uninfected cells.