Cy5标记的DNA荧光毛细生物传感器的研究

摘要

To investigate the feasibility of DNA fluorescence capillary biosensor labeled with Cy5, based on fluorescence capillary analysis (FCA), the DNA biosensor using capillary as immobilization and detection carrier of DNA probe (20-mer-ssDNA) were immobilized on the inner wall of capillary by poly-l-lysine to make DNA fluorescence capillary biosensor (DNA-FCB). The DNA-FCB was hybridized with complementary target DNA labeled by Cy5. The target DNA was qualified or quantified by detecting the fluorescent density of the Cy5 using F-4500 spectrofluorometer. The results showed that the concentration of the target DNA had good linearity with the fluorescent intensity in range of 0.2 ～ 1.2μmol/L when sample volume was 5μL. RSD was lower than 3.5％. The concentration detection limit of the target DNA was 0.39μmol/L. The DNA-FCB can be used to qualify or quantify the target DNA. DNA-FCB is simple with advantages of lower sample and reagent volumes,repeated use of capillary, the lowest test cost, and reduce the pollution to environment.%探索了以Cy5(吲哚-5-菁)作为荧光标记物的DNA荧光毛细生物传感器的可行性.以荧光毛细分析法(fluorescence capillary analysis,FCA) 为基础,在毛细管内壁通过poly-l-lysine将20-mer-ss DNA探针固定,制成DNA荧光毛细生物传感器(DNA fluorescence capillary biosensor,DNA-FCB),DNA-FCB吸入含Cy5标记的靶DNA液杂交,通过检测杂交产物的荧光强度,实现对靶DNA的定性和定量分析.结果显示,样品用量5μL,Cy5标记的靶DNA浓度在0.2~1.2μmol/L (2.4~24mg/L)范围内和荧光强度有良好的线性关系(Y=129.61X+21.233,r=0.9970);RSD<3.5%;检出限为0.18μmol/L.结论:以Cy5作为荧光标记物的DNA荧光毛细生物传感器能达到定量检测靶DNA的目的.该方法操作简便,试样、试剂用量少,毛细管及DNA-FCB可循环使用,测定成本极低,能大大减少环境污染.