Figure 3: (a) The colony formation assay was visualized and evaluated by crystal violet-stained colonies, which showed a significant difference on colony formation between ISL treatment and control. (b) Bar graph showed the differences of colony formation between 15 μg/mL ISL-treated and control groups. Data were presented as mean ± SD for three independent experiments, versus control (0 μg/mL). (c) Effects of 15 μg/mL ISL on the biggest (MAX) and smallest (MIN) colony formation of B16F0 cells (×200). (d) The effect of ISL pretreatment on the formation of tumor in C57BL/6 mice. B16F0 melanoma cells were treated with 15 μg/mL ISL for 48 h prior to s.c. administration. The diameter and size of tumor were also calculated to represent the inhibition of tumor by ISL.