以大豆卵磷脂为研究对象,比较了CTAB法、磁珠试剂盒法以及硅胶膜试剂盒法等3种DNA提取纯化方法。通过大豆内源基因Lectin实时荧光PCR检测,发现CTAB法提取的大豆卵磷脂DNA质量优于其它两种方法,并以CTAB法为基础进行条件优化,进一步提高DNA纯度。采用该方法对6个不同品牌的市售大豆卵磷脂产品进行转基因成分(CAMV35S启动子及NOS终止子)检测,结果证实均不含转基因成分。

The difficulty of detecting genetically modified products lies in DNA extraction from deep-processing products.In this study,DNA from soybean lecithin which was chose as the research object,was extracted and purified by CTAB method,bead kit and NucleoSpin Food kit.The purified DNA was detected by real-time PCR using soybean lectin gene which was one of soybean endogenous genes.The detecting result showed that CTAB method was suitable for DNA extraction of soybean lecithin.By optimizing the conditions of CTAB method,improved Ⅱmethod was determined as the best DNA extraction method for soy lecithin.And DNA extracted by improved Ⅱmethod has high purity.The results of further testing of genetically modified ingredients confirmed that several commercial products were non-GMO.