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.
Standard cell line [e.g. MeWo (ATCC® HTB-65 TM); ARPE19 (ATCC® CRL-2302TM); Vero (ATCC® CCL-81 TM)]
Fluorescently labeled virus stock (genetically engineered VZV-66GFP, HSV1-gC-GFP and PRV-IE180-GFP were kindly provided by Prof. Paul R. Kinchington, University of Pittsburgh, Pittsburgh PA)
Growth medium for the cells listed above (e.g. item #6, Fibroblast medium) Note: However, it can be any other medium for other pairs of virus and cells.
4% paraformaldehyde (EMS 15710) in phosphate buffered saline with divalent cations (e.g. Biological Industries, catalog number: 020201A )
High glucose DMEM (Biological Industries, catalog number: 010551A )
Sloutskin, A. and Goldstein, R. S. (2014). Infectious Focus Assays and Multiplicity of Infection (MOI) Calculations for Alpha-herpesviruses. Bio-protocol 4(22): e1295. DOI: 10.21769/BioProtoc.1295.