火龙果根际土壤微生物2种DNA提取方法的比较

Comparison of Two Extraction Methods in Extraction of Total DNA from Soil Microbes in the Rhizosphere of Pitaya

为获得高质量的火龙果根际土壤微生物总DNA,比较了CTAB-SDS法和SDS法的提取效果,结果表明:2种提取方法均获得约23.1 kb的DNA片段。其中,CTAB-SDS法获得的DNA提取上清液颜色为淡黄色,提取总DNA的量为7.4~7.7 mg·kg^-1,OD 260/280值在1.81~1.95之间,OD 260/230值在1.26~2.03之间,DNA平均质量浓度为0.51 g·L^-1。SDS法获得的DNA提取上清液颜色为深棕黄色,提取总DNA的量为3.5~4.15 mg·kg^-1,OD 260/280值在1.52~1.68之间,OD 260/230值在1.35~1.53之间,DNA平均质量浓度为0.075 g·L^-1。可见,CTAB-SDS法提取DNA的片段较完整,纯度较高,可直接用于后续实验操作,更适用于火龙果根系土壤微生物总DNA的提取。

In order to obtain the total DNA of the soil microbes in the rhizosphere of pitaya(Hylocereus undatus Britt.),two methods,CTAB-SDS and SDS,were used to compare their extraction effect in extraction time,color of DNA supernatant in the extraction process,and total DNA extraction amount and purity after extraction.The results showed that both methods produced DNA fragments with about 23.1kb.With the CTAB-SDS method the color of the supernatant was light yellow;the total amount of DNA extracted was(7.4~7.7)mg·kg^-1;the OD 260/280 value was between 1.81 and 1.95,and the OD 260/230 value was between 1.26 and 2.03;the average DNA concentration was 0.51 g·L^-1.With the SDS method the color of the supernatant was dark brown-yellow,and the total amount of DNA extracted was(3.5~4.15)mg·kg^-1;the OD 260/280 value was between 1.52 and 1.68,and the OD 260/230 value was between 1.35 and 1.53;the average DNA concentration was 0.075 g·L^-1.It was hence concluded that the fragment extracted by the CTAB-SDS method was relatively complete and highly pure,which could be directly used for subsequent experimental operation,and was more suitable for the extraction of total DNA from soil microbes in the rhyzosphere of pitaya.