溴化乙锭标记DNA电化学探针的研究

Studies on the Preparation and Characterization of Ethidium Bromide Labeled DNA Probe

以乙基 -( 3 -二甲基丙基 )碳化二亚胺盐酸盐 ( EDC)为偶联活化剂 ,将电化学活性物质溴化乙锭( Ethidium bromide,EB)成功地标记在人工合成的含有 2 1个碱基的寡聚 DNA片段上 ,制备成 EB标记 DNA探针 ;用电化学方法将待测样品 DNA片段固定在石墨电极表面 ,在一定的温度、p H值和离子强度条件下与EB标记 DNA探针进行杂交反应 ,从而对靶序列 DNA片段进行识别和测定 .此外 ,还讨论了该探针的电化学性质、荧光光谱、待测 DNA片段在石墨电极表面的电化学固定、 DNA链碱基长度对 EB标记 DNA电化学探针的影响以及探针的选择性、重现性和寿命 。

The preparation and characterization of an ethidium bromide labeled DNA probe is studied. Ethidium bromide was labeled onto a 21 bases 5 oligonucleotides by EDC. The electrochemical characterization and fluorescence of the probe is discussed. The accumulation of sample DNA is also discussed. Besides it, the effect of base amounts on labeling and hybridization were discussed. We think the bases between 15—200 are better for electrochemical labeled DNA probe. The EB labeled DNA probe was successfully used to detect sequence specific DNA. It shows a high sensitivity and selectivity. It is hoped for commodity use.