Yuting Deng with Dr. John Yin and Kristen Ann Stauffer

UW-Madison Department of Biochemical Engineering

Variation in the environment around infected cell cultures can help researchers manipulate the virus proliferation rates to establish experiments within a desired time frame. In our research, we investigated the relationship of agar concentration, surface treatment, defective interfering particles and CO 2 on the infection velocity of vesicular stomatitis viruses (VSV-Indiana serotype). Employing the plaque assay and the focal infection techniques, we exposed monolayers of baby hamster kidney cells (BHK-21) to standard VSV and a genetically modified VSV that produces red fluorescent proteins (RFP) instead of green fluorescent proteins (GFP). At methodical times during the virus incubation period, we imaged the infected plates under a Nikon TE300 inverted epifluorescent microscope, revealing the VSV and death fronts of each plaque on fluorescent micrographs to determine the rate of virus propagation. We found a positive correlation between the agar concentration and the VSV proliferation rate and a negative correlation between the defective interfering particles and the virus velocity. We also determined that a gold slide surface pretreated with -COOH terminated SAM slightly reduced the VSV propagation rate verses TCPS and straight gold. A further inspection demonstrated that the naturally occurring GFP-producing VSV has a consistently larger plaque than the modified RFP-producing VSV. Through repeated trials, we have established trends between the environment and VSV propagation rates that enable us to assess the error margins for minor procedural deviations in other experiments.