Development of a Novel Flow Cytometry-Based Titration Assay to Quantify Herpes Simplex Virus Type 1 (HSV-1)

by Brittany P. Lassiter, Adrianna V. Ferraioli, Kenji M. Cunnion, Patric S. Lundberg, and Neel K. Krishna
Volume 15, Issue 1 (Spring 2016)

Plaque assays have traditionally been a reliable way to determine the titer of a lytic virus. However, this method has several shortcomings in that it is time-consuming, labor intensive, and suffers from limited sensitivity. In this article, we describe a novel flow cytometry-based titration assay to quantify green fluorescent protein-labeled herpes simplex virus type 1 (HSV-1-GFP). Using this assay, we were able to directly quantify ten-fold dilutions of the virus in which every GFP-positive cell could be counted. In a head-to-head comparison with a traditional plaque assay, the flow cytometry assay showed a greater linear range and was accomplished in less than half the time of the plaque assay. Additionally, the cells prepared for flow cytometry could also be directly visualized by fluorescence microscopy. These results with HSV-1-GFP show proof of concept and are of practical use to herpesvirus researchers. Additionally, this technique could be easily modified to study other lytic or non-lytic viruses using antibodies against viral antigens...

Lassiter BP, Ferraioli AV, Cunnion KM, Lundberg PS, Krishna NK. Development of a novel flow cytometry-based titration assay to quantify herpes simplex virus type 1 (HSV-1). BioProcess J, 2016; 15(1): 43–8.


Posted online February 17, 2016.