For each tested dilution 0.5 mL of

For each tested dilution 0.5 mL of the test article prior S/D, the test article with S/D and the test article with S/D and C-18 processed was pre-diluted with cell culture medium and 4.5 mL of each pre-dilution were spiked with 0.5 mL PRV (corresponding to spike ratio of 1:10), resulting in the final dilution factors (i.e. prior to inoculation into the cell cultures) with respect to the various prepared test articles.