对于优生优育或慢性疾病（如脑卒中）的防控，以特定基因对高危人群筛查意义重大。叶酸代谢通路中的关键代谢酶5,10-亚甲基四氢叶酸还原酶（MTHFR）的基因型与心脑血管疾病、新生儿出生缺陷等发生密切相关。相比NGS、质谱、生物芯片等，普适准确的基因分型新技术亟需。本项目通过研究核酸适配体与纳米金磁微粒的偶联方法，旨在构建新型核酸适配体-纳米金磁微粒复合探针，研究适配体的构像及其与标记PCR产物末端地高辛亲和结合的关键技术，对等位基因特异性PCR产物的捕获条件进行优化，并结合金磁微粒层析装置实现MTHFR C677T位点的基因分型。拟通过基因组DNA、全血等样本对MTHFR C677T基因分型的系统，建立快速、便捷，准确、普适的基因检测新方法，并开展方法学临床对照研究，为基因筛查方法提供新路径。

For the sake of prenatal and postnatal care, as well as prevention and control of chronic disease (such as stroke), it is very important to screen the specific SNP of high-risk population. The genotype of the key enzyme, 5,10-methylenetetrahydrofolate reductase, in folate metabolism pathway is closely related to cardia-cerebrovascular disease and birth defects. Thus, it is desiderated to develop a new genotyping technique which is simple, accurate and universal compared with NGS, mass spectrum and biochip. In this project, we plan to establish a novel aptamers-GoldMag particle probe through the investigation of the interaction between the aptamers and gold magnetic particles. The investigation of the conformation of aptamers as well as the key factor of affinity capacity of aptamers and Digoxin labelled PCR products will be carried out for the capture of allele specific PCR products. The combination of this aptamers/GoldMag particles complex with lateral flow assay device could be used in the genotype of 677 locus of methylenetetrahydrofolate reductase. A rapid, convenient, accurate and universal genotype method for detection of MTHFR C677T polymorphism will be established by using genome DNA, whole blood as samples, and the clinical study will be carried out as well. The outcomes of this project will contribute to the development of new way for gene screening.