Enumeration of an extremely high particle-to-PFU ratio for Varicella-zoster virus.
Varicella-zoster virus (VZV) is renowned for its low titers. Yet investigations to explore the low infectivity are hampered by the fact that the VZV particle-to-PFU ratio has never been determined with precision. Herein, we accomplish that task by applying newer imaging technology. More than 300 images were taken of VZV-infected cells on 4 different samples at high magnification. We enumerated the total number of viral particles within 25 cm(2) of the infected monolayer at 415 million. Based on these numbers, the VZV particle:PFU ratio was approximately 40,000:1 for a cell-free inoculum.
Carpenter
John E
JE
Central Microscopy Research Facility, University of Iowa, Iowa City, Iowa 52242, USA.
Henderson
Ernesto P
EP
Grose
Charles
C
D002478:Cells, Cultured; D014645:Herpesvirus 3, Human / Q000302:isolation & purification*; D006801:Humans; D008855:Microscopy, Electron, Scanning; D014771:Virion / Q000302:isolation & purification; D014776:Virus Cultivation