Figure 4.

Dose–response curves for the growth factor activity of rat EGF, CBEGF, human bFGF, and CBFGF. BALB/c 3T3 A31 cells (2 × 10⁴ cells in 2 ml of DMEM-2% calf serum) were inoculated onto 6-well multiwell plates, and 7 h later test samples were added. The cell number was determined with a Coulter counter after 4 days culture. The cell numbers in the absence of test samples and in the presence of 10% calf serum were 29,100 ± 1,600 and 239,600 ± 9,900, respectively. Each point represents the mean value ± SEM for triplicate experiments.