Fig. 4.

Cell area changes during low-temperature culture of CHO cells. a Cell surface density and growth is reduced by 48 h of CHO culture at 31 °C compared to 37 °C. n = 3 experiments per temperature and day. b,c Projected cell area of CHO cells cultured at 37 °C and 31 °C, respectively, shows that culture at 31 °C culture results in a sharp decrease in cell area after 48 h. For (b) n = 218 cells at 24 h and n = 494 cells at 48 h in 10 images from 2 pooled experiments, respectively. For (c) n = 217 cells at 24 h and n = 461 cells at 48 h in 10 images from 2 pooled experiments, respectively. (d – g) Exemplary brightfield (transmitted laser light) images of CHO cells with segmentation lines (red) produced by our algorithm cultured at 37 °C for 24 h (d), 37 °C for 48 h (e), 31 °C for 24 h (f), 31 °C for 48 h (g). All graphical data are shown as mean ± sem. * and **** indicate p < 0.05 and 0.0001, respectively (t-test). Scale bar is 100 μm