Lipid content in cells were estimated by red Oil O staining. Cell differentiation was determined by the curve of time-OD value.

• 用油红O染色抽提法测定细胞内脂肪含量，绘制油红O的时间-OD值曲线，观察小鼠前脂肪细胞分化的过程，并对未分化的细胞和可被油红O染成红色的分化的细胞照相。