中文摘要：

目的：探讨聚合酶链式反应-限制性片段长度多态性（PCR-RFLP）法在检定川贝母掺伪中的应用。方法：将川贝母药材DNA与伊贝母药材DNA按不同比例混合,进行PCR扩增,限制性内切酶SmaI作用及琼脂糖凝胶电泳。通过这些实验,可以知道混合样品中伪品的检出限。接着,为了探究本实验中条带灰度与掺伪比例之间的关系,用Image J软件分析凝胶电泳图上的条带,根据未切割条带与切割条带的灰度比,得到标准化值。通过标准化值和掺伪比例2个参数,得到标准曲线,并进行准确性验证。结果：低至0.5%的掺伪比例即可通过该方法被检测。随着掺伪比例增加,未切割条带逐渐增强,切割条带逐渐减弱,两者条带的灰度比值也逐渐增加,到掺伪50%时,几乎没有肉眼可见的切割条带。根据不同掺伪比例对应的标准化值做出标准曲线,经验证该标准曲线的误差率约为0.94%。结论：PCR-RFLP法用于川贝母掺伪检测的检出限为0.5%,灵敏度高;且可通过条带灰度定量的方法反应掺伪比例大小。本研究为改变川贝母PCR-RFLP检验的取样方式和确定取样量提供了实验依据。

英文摘要：

Objective： To explore the utilization of polymerase chain reaction - restriction fragment length polymor- phisms （PCR- RFLP） in the quantification of adulterants in Fritillariae Cirrhosae Bulbus. Methods： The DNA of Fritillariae Cirrhosae Bulbus and the DNA of its adulterants Fritillariae Pallidiflorae Bulbus were mixed with differ- ent proportions, and were treated with PCR amplification, Sinai incubation and agarose gel electrophoresis. By these experiments, the detection limit of the adulterants in the mixed samples was obtained. In order to understand the cor- relation between the grayscale of the bands and the proportion of the adulterants, the grayscale of the bands in the gel map was analyzed with Image J software, the standard value was obtained according to the ratio of grayscales be- tween the uncutted bands and the cutted bands and then the standard curve was profiled according to the parameters of the standard value and the proportion of the adulterants. Further, the accuracy of the standard curve was verified with specific examples. Results： This method can detect as low as 0.5 % proportion of the adulterants. With the in- creasing proportion of the adulterants,the uncutted bands became stronger and the cutted bands went weaker. The grayscale ratio of the uncutted bands to that of the cutted increased accordingly. When the proportion of the adulter- ants reached to 50%, there were nearly no visible cutted bands. The error rate of the standard curve was about 0. 94% according to the verification. Conclusion：The method of PCR - RFLP for the identification of the adulterants in Fritillariae Cirrhosae Bulbus is sensitive with the detection rate as low as O. 5%. Furthermore, it is possible to- know the approximate proportion of the adulterants by measuring the grayscale of the bands on the map of agarose gel electrophoresis. This research provides with the experimental evidence for the rational way of sampling and the a- mount of sampling for examining Fritillariae Cirrhosae Bulbus samples wit