Methods The cultured osteoblast-like cells in vitro were isolated from fetal rat calvaria and the effects of PDGF on cellular DNA contents were observed under flow cytometer.

• 方法从胎鼠颅骨分离、培养成骨细胞，应用流式细胞仪观察PDGF对成骨细胞DNA合成及细胞周期的影响；