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.
Tag: <span>flow cytometry</span>
Many laboratories have utilized cell-free systems or prokaryotic systems designed to produce biological molecules with single polypeptide chains, limited folding requirements, and without glycosylation. The yeast systems are used to generate glycoproteins; however, their glycosylation profiles are vastly different from those of mammalian cells. Without significant glycoengineering, the yeast-produced recombinant glycoproteins may be unsuitable as therapeutic molecules. As such, the use of mammalian cells is still the preferred method to produce complex biological molecules…