Abstract
Titration of viral stocks is a critical process before any experimental use of the virus. Here we describe an infectious focus assay for several alphaherpesviruses, a titration method for fluorescently labeled viruses, based on the original plaque assay. In addition, the calculation of multiplicity of infection (MOI) is presented.
Keywords: Multiplicity of infection, Viral infection, Herpesvirus
Materials and Reagents
Equipment
Procedure
Representative data
Figure 1. Microscopic appearance of infectious foci using fluorescent virus. ARPE19 (A, B) or MeWo (C, D) cells were infected with cell-associated VZV-23GFP. Both fluorescence (A, C) and phase contrast (B, D) images of the same fields are shown. Scale bar =200 µm Figure 2. Plaque assay for HSV1 gCGFP using crystal violet staining. 4 days after infection, cells were fixed and stained as described in the text. Viral concentration is decreasing from left to right. Crystal-violet stains the cells, which allows the visualization of the clear plaques. An arrow points to the dilution which yielded quantifiable plaques. Control, uninfected wells did not yield any detectable plaques (uninfected).
Recipes
Acknowledgments
The HSV1 titration was based on an unpublished protocol of Dr. Maya Ilouze (Sheba Medical Center, Tel-HaShomer, Israel). We gratefully acknowledge the support of grant from the Israel Science Foundation 238/11 and a donation from the Maximillian Goode Foundation.
References
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