一种鉴别CCC型质粒带的简便方法

A Simple Procedure for Discriminating the CCC Plasmid DNA

用单向二步琼脂糖凝胶电泳可鉴别金黄色葡萄球菌质粒谱中的CCC型质粒带。先将质粒DNA样品进行琼脂糖凝胶电泳,再将电泳后的凝胶板置于2.537×10^(-7)m紫外灯下10 cm处照射25 min后,在同方向下进行第二步电泳,分子量为1.69±0.05～22.24±0.73 Md的CCC型质粒均可出现肉眼可见的OC型带;非CCC型质粒无OC带出现,据此可判别金黄色葡萄球菌中绝大多数菌株的CCC型质粒带和被染色体DNA带所掩蔽的质粒。

A simple method for discriminating the CCC plasmids and detecting the plasmids covered by chromosomal DNA in the plasmid profiles of Staphylococcus aureus was presented. A two-step procedure of agarose gel electrophoresis in one direction was used, being made after the 2.537×10^(-7) ultraviolet light irradiation (Distance: 10cm, Time: 25 min). It introduced single-strand nicks in DNA inserted by ethidium bromide and converted CCC into OC forms. The CCC plasmid DNA bands in 90% of the strains tested can be detected. Also, the plasmids covered by chromosomal DNA bands in the total strains can be discriminated.