Fig. 3.

Growth phenotypes of a ts (CRS2) and a qi (CRS4) mutant. Cell lysates from 33 °C cultures were collected at full CPE. Mutant CRS2 was harvested from transfections and mutant CRS4 after the first passage on fresh HeLa cells. (a) The lysates were titrated at three different temperatures (33, 37 and 39.5 °C) by plaque assay (see Methods). (b) Pictures of plaque assays were taken at different virus dilutions, as indicated in the centre of the well. The plaques of variant CRS4 obtained after the first passage (P1) are shown.