Semagn Kassa
International Maize and Wheat Improvement Center (CIMMYT), Nairobi, Kenya.
Methods Mol Biol. 2014;1115:53-67. doi: 10.1007/978-1-62703-767-9_3.
Taxonomists must be familiar with a number of issues in collecting and transporting samples using freezing methods (liquid nitrogen and dry ice), desiccants (silica gel and blotter paper), and preservatives (CTAB, ethanol, and isopropanol), with each method having its own merits and limitations. For most molecular studies, a reasonably good quality and quantity of DNA is required, which can only be obtained using standard DNA extraction protocols. There are many DNA extraction protocols that vary from simple and quick ones that yield low-quality DNA but good enough for routine analyses to the laborious and time-consuming standard methods that usually produce high quality and quantities of DNA. The protocol to be chosen will depend on the quality and quantity of DNA needed, the nature of samples, and the presence of natural substances that may interfere with the extraction and subsequent analysis. The protocol described in this chapter has been tested for extracting DNA from eight species and provided very good quality and quantity of DNA for different applications, including those genotyping methods that use restriction enzymes.
分类学家必须熟悉使用冷冻方法（液氮和干冰）、干燥剂（硅胶和吸水纸）以及防腐剂（十六烷基三甲基溴化铵、乙醇和异丙醇）来采集和运输样本时的诸多问题，每种方法都有其自身的优缺点。对于大多数分子研究而言，需要质量和数量都较为理想的DNA，而这只能通过标准的DNA提取方案来获得。有许多DNA提取方案，从简单快速但产生低质量DNA却足以用于常规分析的方案，到通常能产生高质量和大量DNA的繁琐耗时的标准方法不等。要选择的方案将取决于所需DNA的质量和数量、样本的性质以及可能干扰提取和后续分析的天然物质的存在情况。本章所描述的方案已针对从八个物种中提取DNA进行了测试，并为不同应用提供了质量和数量都非常好的DNA，包括那些使用限制酶的基因分型方法。
