Fig. 1.

Optimisation of IncuCyte ZOOM software parameters for accurate counting of NS5A-positive cells. Images from a microtitre plate were analysed eight times, using various permutations of software parameter conditions (area filters, RCU threshold and the degree of cell-edge splits). Total “red cells per well” was calculated and extrapolated to produce viral titre in IU/mL (left axis). Data represents the mean + SEM of titres calculated from three wells across the linear range of dilutions. The combination of −30 edge split, 2.5 RCU threshold and 300–4000 μm² area filters produced results most similar to those from the manual counting method, as indicated on the right axis (FFU/mL).