近年来，随着生物医学研究的深入发展，人们发现单核苷酸多态性（Single nucleotide polymorphisms, SNPs）与一些基因型疾病密切相关。基因中SNPs的超灵敏研究可以实现对疾病相关基因的定位研究。SNPs技术发展迅速，但设计一种高通量、简便、灵敏度高、准确性好的SNPs检测法仍是有待解决的问题。本工作中我们设计了一种利用DNA滚环扩增（Rolling circle amplification, RCA）反应检测SNPs的思路。本实验中，我们选取野生型和突变型靶标DNA序列，并设计相应锁式探针和引物DNA，进行室温下RCA反应。我们对扩增产物进行凝胶电泳分析，检测扩增反应是否成功进行，从而确定靶标DNA是否发生单碱基错配。实验结果表明：基于RCA反应可以超灵敏检测SNPs。凝胶电泳图显示，野生型靶标序列扩增时，扩增产物对应孔道中有明亮的产物条带且靠近加样孔，而突变型靶标序列扩增时，扩增产物对应孔道只有扩增前模板和引物杂交条带。所以野生型靶标序列能顺利进行碱基互补配对并扩增，而突变型不能顺利进行RCA反应。这种基于RCA反应的SNPs检测法将DNA扩增过程与检测过程相结合，灵敏度更高且更简便，对核酸检测领域的发展具有重要意义。

In recent years, with the in-depth development of biomedical research, it has been found that single nucleotide polymorphisms (SNPs) are closely related to some genotype diseases. Hypersensitive detection of SNPs in genes can be used to localize disease-related genes. With the rapid development of SNPs detecting techniques, it is still a problem to be solved to design a high throughput, simple, sensitive and accurate detection method for SNPs. In this work, we designed a method for SNPs detection with rolling circle amplification (RCA) reaction. We selected the wild and mutant target, designed the corresponding locking probe and primer DNA, and conducted RCA reaction at room temperature. We performed agarose gel electrophoresis analysis on the amplification products to detect whether the amplification reaction was successful, so as to determine whether the single base mismatch occurred in the target DNA. Experimental results show that SNPs can be detected sensitively based on RCA reaction. Gel images showed that there was bright band of DNA amplification product near the sample well for the wild target and only the band of the complex of template and primer for the mutant target. Therefore, the wild target could successfully lead to the reactions of base pairing and amplification, while the mutant target could not. This detection method for SNPs based on RCA reaction combines the processes of DNA amplification and detection, which is more sensitive and simple, and is of great significance to the development of nucleic acid detection.