用普通琼脂糖代替低熔点胶回收DNA片段

为了建立一种直接从普通琼脂糖凝胶中回收DNA片段的简便实用的方法,采用聚合酶链式反应扩增人P53基因外显子7、8和其间的内含子7序列,用普通琼脂糖凝胶电泳,直接从凝胶中切下产物带,用加热熔化法回收DNA;紫外比色法测定回收率;用测序法鉴定回收产物质量。并用QIAquick Spin纯化柱对照。结果表明,本法回收的产物质量明显优于用QIAquick Spin柱回收,本法回收的产物用于测序效果极佳,回收率达80％,用QIAquick Spin柱回收率不到20％,差异非常显著（P<0.01）。证明这种方法回收PCR产物质量可靠,能代替低熔点胶回收DNA,有较大的实用价值。 Abstract： In order to find a simple and efficient method to isolate single or double?strand DNA fragment amplified by polymerase chain reaction (PCR),we used PCR method to amplify exon 7,exon 8 and intron 7 of human P53 gene, electrophoresis to identify products,fusion and phenol-chlorofom extraction (FPC) to isolate specific DNA from agarose gel,ultraviolet colorimetry to deteminate collected rate,and direct sequencing to identify the quality of recollected DNA. A control test was also made by using QIAquick Spin Colum．The results showed that the quality of PCR products recollected by using FPC method was very good．When the recollected DNA was used in sequencing,no matter what was single or double-strand DNA,the sequence data was clear and even,with low noise．The recollected rate of using FPC,which was over 80 per cent, was higher than that of using colum (lessthan 20 per cent), there were statistical significances (P<0.01).In the control test, it had a little non-specific DNA in the collected products,and the sequencing experiment of using double-strand products was failure．All above mentioned suggested that general agarose gelis efficient in place of low melting-temperature for isolating DNA fragment．     

羧酸化环糊精复合的银纳米簇的合成及其抗菌能力测试

本研究以羧甲基-β-环糊精（CM-β-CD）为模板合成 AgNCs,探讨了 AgNCs 的合成条件,对其进行了表征,并对其抗菌能力进行了研究。结果显示,当溶液的 pH 值为5．98,CM-β-CD 和 AgNO3的比例为1∶1时,合成的银纳米簇荧光强度达到最大。以大肠杆菌为研究对象,对环糊精合成的银纳米簇进行抗菌实验测试,发现由于银纳米簇比表面较大,表面活化能高使其比银离子和银溶胶具有更好的抑菌能力。