TABLE 2.

Average particle-to-PFU, particle-to-ICP4 FFU, and ICP4 FFU-to-PFU ratios of stocks of HSV-1 strain 17 and mutant viruses on different cell typesa

VirusVero cellsU2OS cellsHFFF-2 cells
Particles/PFUFFU/PFUParticles/FFUParticles/PFUFFU/PFUParticles/FFUParticles/PFUFFU/PFUParticles/FFU
Strain 17322.116583.7231570.9148
dl14034593316322.02822,40075605
FXE2101911745.61227,00086320
  • a ICP4 FFU titers were determined 6 h after infection. The data show averages of the ratios of five stocks of strain 17, four stocks of dl1403, and one stock of FXE. The degree of variation in these ratios between individual stocks was according to the variability described in Table 1, footnote a.