The Preparation And Preliminary Application Of Nucleic Acid Probes

Nucleic acid carries and transmits the hereditary information of the life. It notonly play an important role in continuing the living beings, keeping the hereditarycharacteristic of the biological species, but also have a close relation with thebiomutation. It can contribute to people's finding out about the essence of thebiological phenomena from the molecule level to study the nucleic acid, especially thestructure and function of the nucleic acid. The probe technology of nucleic acid isimportant means to study the nucleic acid structure and function. The preparation andmark of the nucleic acid probe are keys to the probe technical development of nucleicacid, study and set up new preparation probe technologying has important theorymeaning and using value. This thesis have systematically studied the preparation andpreliminary application of the nucleic acid molecular "light switch"and MNP-ssDNAprobe and have obtained the following results.(1) Ru(bipy)₂(dppz)²⁺ and Safranine T are used as the fluorescence probe. Theinteractions of two fluorescent molecules, Ru(bipy)₂(dppz)²⁺ and Safranine T, onPNA-DNA and dsDNA are studied respectively. When the same fluorescent molecularreacts with these two different targets, the distinct fluorescence is observed under thesame conditions. This experimental result demonstrates that the interaction betweenthe probe and PNA-DNA is different from that between the probe and dsDNA. Wethink that there are must be some difference between PNA-DNA and dsDNA instructure. UV spectra was also used to confirm our conclusions.(2) An asymmetric PCR technique based on magnetic nanoparticles (MNPs) has beendeveloped in this work to generate the MNP-ssDNA probe. One of the twoamplification primers was bound to the MNPs surface by modifying its 5'-end andleaving the 3'-end available for DNA polymerase activity, while the other wasunbound. The results obtained showed that PCR could proceed successfully andplenty of target ssDNA connected with MNPs (MNP-ssDNA complexes) along withsome dsDNA with one strand connected to MNPs could be generated. In virtue oftheir immobilization on the MNPs surface, asymmetric PCR products could be easily...