量子点标记的基因芯片在食源性致病细菌检测中的应用

DETECTION OF FOOD-BORNE PATHOGENIC BACTERIA BY OLIGONUCLEOTIDE MICROARRAY WITH STREPTAVIDIN-CdSe/ZnS QUANTUM DOTS AS FLUORESCENT LABELS

目的基于链霉亲和素修饰的CdSe/ZnS量子点标记的基因芯片技术,建立快速、准确、高通量的检测食源性致病细菌的方法。方法以16s rDNA为靶基因,针对待检的食源性致病细菌合成一系列寡核苷酸探针,制成寡核苷酸芯片,生物素化标记的PCR产物与芯片杂交,然后用链霉亲和素修饰的CdSe/ZnS量子点进行标记,应用激光共聚焦扫描仪进行信号的检测。对量子点标记的基因芯片技术平台的特异性、敏感性和重复性进行评估。结果链霉亲和素修饰的CdSe/ZnS量子点标记的基因芯片可有效区分常见致病细菌,检测灵敏度为10 cfu/ml,变异系数<10%。结论链霉亲和素修饰的CdSe/ZnS量子点标记的基因芯片可对致病细菌进行快速检测鉴定,其敏感性和重复性良好。

Objective To establish an oligonucleotide microarray technigue for detection of food-borne pathogenic bacteria coupled with streptavidin-CdSe/ZnS quantum dot as fluorescent labels. Methods Oligonucleoti- de probes targeted on 16s rDNA were designed and synthesized to create an oligonucleotide microarray. The PCR products labeled by biotin were hybridized with the oligonucleotide microarray, then the streptavidin-CdSe/ZnS quantum dots were incubated with the microarray. PerkinElmer scanarrayGx scanner was used to detect the fluores- cent signals. The specificity, repeatability, and sensitivity of the oligonucleotide microarray were estimated. Results The microarray system labeled by streptavidin-CdSe/ZnS quantum dot can successfully discriminate the bacterial pathogens to the species level. The specificity and repeatability was good, the sensitivity was 10 cfu/ml, and the variation coefficient was〈 10. Conclusion The oligonucleotide microarray coupled with streptavidin-CdSe/ZnS quan- tum dot as labels was proved to be a quick and efficient universal identification system for pathogenic bacteria.