Figure 5. Defining the titration time for different viruses.

MV-Halle (panel A), wt MV-G954 (panel B), and VSVeGFP (panel C) stocks were used in 3-fold serial dilutions to infect Vero, Vero-SLAM and Vero cells, respectively. At different times post infection, cells were collected and analyzed by flow cytometry to determine infected cells for each virus input. The optimal time for virus titration reflects the first overlap between the peaks of the most concentrated dilution and the adjacent one and is marked with a “star” on the corresponding histogram. For each dilution, titers have been calculated by applying the Poisson law, and values expressed in IU/ml as function of the inoculation volume (see the charts below the histogram panel for each virus). The red curves reflect the time when a single replication cycle has occurred. The titer is determined by the average of the values on the level curve (red) and is compared to the titer obtained by TCID50 technique below each chart.