用限制性稀释法对食管癌EC9706细胞系进行单细胞克隆分离，建立了3个亚系，分别命名为EC1、EC2和EC3。细胞遗传学分析显示，EC1仍为混合克隆，EC2和EC3的染色体众数分别为117条和62条。对EC2和EC3的生物学特性进行比较，生长曲线、平皿集落形成能力实验、流式细胞分析和细胞运动能力实验均表明，两者的恶性程度有显著差别，EC2较低，EC3较高。成功分离的2个食管癌单克隆细胞亚系，可为食管癌发生发展的分子机制研究、基因治疗研究、耐药机制研究以及抗肿瘤药物筛选提供实验材料。

Cell line is one of the important materials for cancer research. In the present study, single-cell clones were isolated from esophageal carcinoma cell line EC9706 by limited dilution method. Three sublines were obtained, namely EC1, EC2 and EC3. Cytogenetic analysis showed that EC1 was a mixed clone, and the chromosome number of sublines EC2 and EC3 were 117 and 62, respectively. There were significant differences in the growth rate, cell cycle distribution, cell mobility, and colony formation ability between EC2 and EC3. The degree of malignancy was significantly higher for EC3 than for EC2. The monoclonal sublines EC2 and EC3 with different malignant potential provide useful materials for exploring the pathogenesis and gene therapy of human esophageal carcinoma, investigating multidrug resistance, and screening anti-tumor medications.