新型压电DNA石英传感器快速检测结核分枝杆菌

A novel DNA piezoelectric quartz sensor for rapid detection of Mycobacterium tuberculosis

目的设计一种新型的压电DNA石英传感器用于检测结核分枝杆菌。方法将巯基修饰寡核苷酸探针以自组装方式固定于压电石英晶振的金电极表面,取适量培养基上的标准菌株或痰样,加DNAzol提取,离心得到DNA沉淀,加Btg I限制性内切酶切出其IS6110片段。根据杂交前后晶体振荡频率的变化判断是否存在结核分枝杆菌。该压电DNA石英传感器优点在于无需PCR扩增,扩大了该技术的适用范围。结果本文设计的传感器最佳修饰探针浓度为1.5μmol/L,热处理后加入封闭寡核苷酸有效避免DNA复性,放大响应信号。与PCR扩增结果对比,临床阳性样品与传感器探针杂交后能引起频率明显下降,阴性样品没有明显的频率响应,两者结果一致。结论该传感器能有效区分结核分枝杆菌与其他临床常见病原微生物,具有良好的专属性。

Objective To design a novel DNA piezoelectric quartz sensor for the rapid detection of Mycobacterium tuberculosis.Methods The thiol- modified probe was immobilized on the gold electrode surface of quartz crystal by self- assembled monolayer method. Standard strains or sputum samples from the culture media were taken for extraction by adding DNAzol,concentrated for DNA precipitate,and then IS6110 fragments were digested by Btg I restriction enzyme. According to the change of the crystal oscillation frequency before and after hybridization,to determine the existence of Mycobacterium tuberculosis. The piezoelectric DNA quartz sensor had the advantage of no PCR amplification,which expanded the application scope of the technology.Results The optimum concentration of the established probe in this paper was 1. 5 μmol / L. After heat treatment,the closed oligonucleotide was added to avoid the DNA complex,so as to amplify the response signal. Compared with the results of PCR amplification,the clinical positive samples and sensor probe,after hybridization,can cause significant decline in frequency,while negative samples did not have a clear frequency response,and the both results were consistent. Conclusion The sensor can effectively distinguish between Mycobacterium tuberculosis and other common clinical microbiology,which is of good specificity.