Figure 4

Mitogenic activity of FGF1s towards FGFR1c-Ba/F3 cells. (a) FGFR1c-Ba/F3 cells were cultivated for 48 h with the indicated concentrations of FGF1s in the presence of 10 μg/ml heparin (closed symbols). TetraColor ONE was then added, and the cells were incubated for an additional 4 h, after which the absorbance at 450 nm was measured. No mitogenic activity was seen in the absence of heparin (open symbols). (b) In the absence of the FGF1s, no activity was observed, despite the presence of heparin. The data presented are the averages and standard deviations of a triplicate experiment. Independent experiments were performed twice, and essentially the same results were obtained.