简述克隆技术建立肿瘤细胞株的方法及特点。
参考答案：
方法：利用克隆技术建立肿瘤细胞株，选择克隆形成率高的肿瘤细胞株移植到动物体内诱发转移灶，取转移灶肿瘤组织，再经体内筛选，呈高转移模型。
特点：
①能100%的确保建株的细胞来源于母系肿瘤细胞中的一个。
②各克隆化的细胞株是在相同条件下培养传代。
③均使用同一品系的裸鼠并在同一条件下饲养客观反映了不同肿瘤细胞株间恶性类型。
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