Figure 3: Clonogenic tests on L-02 (a) and Hep G2 (b) cells following X-ray treatment. The cell strains were treated in the presence of protein or amifostine and irradiated with 2 Gy X-ray subsequently. After irradiation, the cells were detached with trypsin-EDTA and plated at a concentration of 100 cells/dish in drug-free medium. Fourteen days later the colonies were fixed and counted by using a crystal violet staining to evaluate the number of colonies present in the dishes. (c) Comparison of protective rate between three proteins and amifostine. The bars indicate the means ± SD (, compared with group received irradiation only, , ).