FIG. 2.

Analysis of bacmid and virus propagation in Sf9 cells. (A) GUS-staining assays of Sf9 cells transfected or infected with vAcAN-KO/GUS, vAcAN-KO/GUS-Res, and vAcIEGUS. The transfected cells were incubated for 5 days. A total of 100 μl of supernatants from each transfected sample was added to freshly prepared Sf9 cells and incubated for 3 days. After fixation, cells were stained with X-Gluc and incubated overnight at 37°C. Images A, C, and E: cells were transfected with vAcAN-KO/GUS, vAcAN-KO/GUS-Res and vAcIEGUS, respectively, and they were stained at 5 days p.t. Images B, D, and F: cells were infected with supernatants from the cells shown in images A, C, and E, respectively, and stained at 3 days p.i. The white arrows in image A indicate two cells that tested positive for GUS expression. (B) Virus growth curves from supernatants of transfected and infected cells. The virus titer was determined by measurement of doses that were 50% tissue infective for Sf9 cells. Each experiment was performed in triplicate.