Doubling time and morphology of primary K9TCC cells. The doubling times for (A) K9TCC#1Lillie (passage #6) was dt = 47.4 hours, (B) K9TCC#2Dakota (passage #5) was dt = 31.96 hours, (C) K9TCC#4Molly (passage #4) was dt = 44.69 hours, and (D) K9TCC#5Lilly (passage #4) was dt = 48.3 hours. Values were represented as the mean ± S.E. (n = 3 for each time point). The representative images of K9TCC cell morphology were taken by phase-contrast microscope and are shown in insets of graphs. Objective 20× with scale bar 50 μm.