红壤中微生物总DNA的分离与纯化

采用2种不同的土壤DNA直接提取方法,提取了4种不同类型红壤的微生物总DNA,并对提取的DNA用Sephadex G-200离心层析法进行了纯化。结果表明:2种方法都可以从红壤中提取到分子量大于10kb的DNA的片段,不同提取方法获得的DNA的产量存在较大差异。方法二用冻融进行预处理再结合SDS和溶菌酶的化学裂解方法,是效果较好的DNA抽提方法。其提取DNA产量高,重复性好,适合于土壤少量样品的DNA提取。Sephadex G-200离心层析法能较好地去除土壤中的有机物杂质,DNA溶液由原来的黄褐色变得澄清透明,且不会使提取的DNA断裂或损失,是一种较好的土壤微生物总DNA纯化方法。

Extraction and purification of microorganisms total DNA from red soil

Direct extraction of soil DNA has become essential for the study of soil microorganisms.Here,we used two different direct methods of extracting DNA from four types red soil and purified the soil DNA using Sephadex G-200 gel filtration.The result shows that both of the two procedures can obtain DNA fragment over 10 kb from soil.But the yields of DNA with different methods are different.Method two was found to be the best DNA extraction procedure in which freeze thawing combined with SDS and lysozyme.It is of high production and good reproducibility and is suitable for extracting DNA from small amount of soil sample.Sephadex G-200 spin column purification was found to be the best method for removing humic substances while minimizing DNA loss during purification.