QIAGEN Plasmid Midi Kit (25)，12143，Qiagen，凯杰

 QIAGEN Plasmid Kits应用重力流阴离子交换柱纯化转染级质粒DNA。该试剂盒可纯化获得至多10 mg的质粒DNA。离心获得澄清的裂解产物和异丙醇沉淀。

     QIAGEN Plasmid Kit利用重力流QIAGEN阴离子交换柱技术高效纯化质粒DNA。产量可达10 mg（Giga）、2.5 mg（Mega）、500 µg（Maxi）、或100 µg（Midi）高拷贝质粒DNA（培养体积取决于质粒拷贝数、插入片段大小、宿主菌株和培养基。）QIAGEN Plasmid Kits纯化的质粒DNA适合多种应用，如：转染、克隆和体外转录。

    QIAGEN-tips内独特的阴离子交换树脂专为纯化核酸设计。它独特的分离特性，使纯化的DNA的纯度相当于连续2次CsCl梯度离心得到的DNA纯度。预装的QIAGEN-tips利用重力流原理工作，缩短了纯化质粒的手动操作时间。整套QIAGEN质粒纯化体系避免苯酚、氯仿、溴化乙锭和CsCl等有毒物质，减小对使用者和环境的危害。

      使用QIAGEN Plasmid Kits，细菌裂解物通过离心澄清。澄清后的裂解物上样到阴离子交换柱，质粒DNA在适当的低盐条件和pH条件下与树脂进行选择性结合。RNA、蛋白质、代谢产物和和其它低分子量杂质用中盐洗涤液去除，用高盐缓冲液洗脱纯质粒DNA（参见"QIAGEN Plasmid Kit procedures"）。得到的DNA用异丙醇沉淀浓缩和脱盐后，离心收集。

Transfection efficiency versus plasmid purification method.

Different pRSVcat DNA preparations using the methods indicated were introduced into the indicated cell lines by liposome-mediated transfection, and the efficiencies determined by measuring CAT expression levels after 40 h. Each bar represents the mean of 4 independent transfections (2 transfections with each of 2 independent plasmid preparations). The highest transfection efficiency was achieved with QIAGEN Plasmid Kits.

QIAGEN Plasmid Kit procedures.

Neutralized bacterial lysates are cleared by centrifugation. The cleared lysate is then loaded onto the anion-exchange tip where plasmid DNA selectively binds under appropriate low-salt and pH conditions. RNA, proteins, metabolites, and other low-molecular-weight impurities are removed by a medium-salt wash, and ultrapure plasmid DNA is eluted in high-salt buffer. The DNA is concentrated and desalted by isopropanol precipitation and collected by centrifugation.
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QIAGEN Plasmid Kits纯化质粒DNA适合多种应用，如：

• 转染

• 克隆

• PCR
• 体外转录