3种真核藻类DNA提取方法比较

Comparison of Three Extraction Methods for DNA from Eukaryotic Algae

目的建立一种简单、快速、高效的从自然水样中提取藻类总DNA的方法。方法通过DNA产物的浓度和纯度、DNA产物的完整性及PCR扩增的比对,对3种真核藻类DNA的提取方法 [纤维素酶法、改良十六烷基三乙基溴化铵(CTAB)法和超声波破碎试剂盒法]进行比较。结果 3种方法得到的基因组DNA均较完整,片段大小都在23 kb左右;且3种方法得到的DNA浓度均较高。CTAB法和试剂盒法提取得到的总DNA A_(260nm)/A_(280nm)的比值分别为1.767和1.824,并且A_(260nm)/A_(230nm)比值均在1.9以上,说明提取得到的总DNA纯度较高,且PCR产物经1.5%琼脂糖凝胶电泳检测得到明亮的条带。而纤维素酶法得到的DNA的A_(260nm)/A_(280nm)比值与A_(260nm)/A_(230nm)比值分别为1.617和1.522,表明盐及蛋白质污染较前两者严重。结论综合考虑后,认为CTAB方法更适合从自然水样中提取藻类DNA。

Objective To construct a simple, rapid and high-quality algae DNA extraction method from natural water sample. Methods Three DNA extraction methods, including the cellulase, the improved CTAB and the commercial kit methods, were compared based on DNA yield, purity, size and PCR amplification in this paper. Results The integrity of chromosomal DNA molecules was good for the three methods and the size of fragments was about 23 kb.The three methods all had a higher concentration. The A260/A280 of total DNA extracted from CTAB and kit methods were 1.767 and 1.824 respectively, and the A260/A230 were both above 1.900, which explained that both methods had high purity. While the A 260/A280 and A 260/A280 of total DNA extracted from cellulose enzymatic method were 1.617 and 1.522 respectively, which showed that the DNA was seriously polluted by salt and protein. Conclusion CTAB method is a better way for the algae DNA extraction from natural water sample.