Fig. 2.

Clonogenic assay performed in 35 mm dish, with clones produced by SCC-9 tumor cells. A. Assay procedure and micro pipetting B. Incubation in CO₂ incubator at 37 °C. C. Untreated SCC-9 control cells. D. Colonies produced after treatment with ECF of EE – 40 μg/ml. E. Colonies produced after treatment with ECF of EE – 80 μg/ml. F. Colonies produced after treatment with ECF of EF - 40 μg/ml. G. Colonies produced after treatment with ECF of EF – 80 μg/ml. H. Colonies produced after treatment with ECF of PE – 40 μg/ml. I. Colonies produced after treatment with ECF of PE – 80 μg/ml. ECF of EE and PE were most efficient in colony formation inhibition.