FIG. 2.
Accumulation of lacZ mutations during serial passage of CMVLacSV40Puro. Viral particles containing two CMVLacSV40Puro genomes were serially passaged on 293T cells, and mutations in the lacZ indicator gene were monitored by determining the number of white colonies following staining with X-Gal. The solid line connects the mean data from three experiments, and the error bars represent standard deviations of the means. The dotted line represents the least-squares fit for a line representing the data by the equation y = 5.8x + 2.7 (r2 = 0.92).