转基因食品DNA提取技术研究

DNA extraction from GM foods

目的:建立从食品中提取DNA的方法。方法:采用CTAB法、酶裂解法、SDS沉淀法3种方法提取转基因相关食品中的DNA,用核酸蛋白分析仪测定核酸的纯度和浓度、PCR扩增真核生物的18SrDNA基因评价提取核酸的质量。用转基因植物通常含有的CaMV35S启动子作为转基因成分的指示标记。结果:3种方法得到的DNA提取物OD260/OD280比值均接近1.6～1.9,CTAB法获得的DNA量较少,酶提取法所得的DNA提取物的量多,但扩增条带荧光较暗。SDS法能收获较多的DNA,PCR扩增效果好。用SDS法提取的DNA进行35S启动子检测,3份转基因样品均出现强阳性结果,而10份非转基因食品均未产生阳性条带。结论:SDS沉淀法提取DNA,具有经济、简便的特点,所提的DNA量适用于PCR检测。

Objective:To establish a method for extracting DNA from foods.Methods: DNA was extracted from soybean, maize and their processed foods by CTAB method, enzymatic hydrolysis method and SDS method, respectively.The purity and concentration(were determined).The quality of the extraction by 18S rDNA was evaluated with PCR technique.The promoter CaMV35S was used as an indicator for GM foods.Results: The OD 260/OD 280 of DNA extraction by three methods was all in the range of 1.6~1.8.The amount of DNA extraction obtained by CTAB method was small, but that obtained by enzymatic hydrolysis method was large.Their electrophoresis stripes radiated dim fluorescence.The amount of DNA extraction obtained by SDS method was large and its electrophoresis stripe radiated bright fluorescence.During determination of promoter CaMV35S, three samples (the DNA extraction from GM foods by SDS method) all showed strong positive results, while 10 controls (the DNA extraction from non-GM foods by SDS method) all showed negative results.