本文以原位缺口平移技术,比较了个体有丝分裂细胞NOR转录活性及DNaseⅠ敏感性,并以限制性内切酶MspⅠ及HpaⅡ为切口剂进行修饰。结果表明,在中期细胞活性NORs对DNaseⅠ的消解十分敏感,它们的甲基化程度比无活性的NORs为低。单层培养的人原代皮肤成纤维细胞经胰蛋白酶作用后,转移到35mm含有消毒玻片的塑料佩特里细菌培养盘中,培养两天后行常规细胞染色体制备。固定后玻片立即用10mMTris-HCl(pH7.4)液洗涤细胞。并 In this paper, in situ nick translation technique was used to compare the NOR transcription activity and DNase I sensitivity of individual mitotic cells, and modified with restriction endonucleases Msp I and Hpa II as incision agents. The results showed that in the metaphase cell viability, NORs were very sensitive to digestion of DNase I and their methylation was lower than that of inactive NORs. Monolayer cultured human primary dermal fibroblasts were trypsinized, transferred to a 35 mm plastic Petri dish containing disinfection slides, and cultured for two days prior to routine cell chromosome preparation. Immobilized slides were immediately washed with 10 mM Tris-HCl (pH 7.4). and