Nucleus was stained purplish-blue.The thymocyte of positive group had decreased obviously.The apoptotic body had been phagocytosed by macrophages.

• 空白对照组的胸腺细胞体积中等大小,呈圆形或椭圆形,胞膜完整光滑,胞核比较大,核质致密,染成紫兰色,胞浆量少。