Fig. 3. Growth rates of CS-2, CS-3, CS-4, and CS-8 cell lines. A, PD versus time in culture from 0 to 40 days of culture. The arrow points to a period when growth rates reached a brief plateau. Regression analysis of growth prior to the plateau is indicated by the solid line, and analysis of postplateau growth is indicated by the dashed line. Slopes and regression parameters for the two analyses are indicated. B, PD versus time in culture from 0 to150 days of culture.