FIG. 3.

Binding and infectivity of HT1080 cells pretreated with VSV-G. (a) Fluorescence-activated cell sorting analysis of VSV-G vesicles bound to HT1080 cells. HT1080 cells were incubated with two different amounts of VSV-G vesicle, and binding of VSV-G to the cell surface was detected by reaction with antibody I1 to VSV-G followed by labeling with fluorescein isothiocyanate-coupled anti-mouse secondary antibody. In all cases, a total of 10,000 events were visualized. (b) Infectivity of HT1080 cells expressed as the number of G418-resistant colonies following GPR infection of HT1080 cells preexposed to 1 to 100 μg of VSV-G protein. The concentration of VSV-G is in the range of 0.5 to 50 μg/ml.