The Study Of The DNA Fluorescence Probe

Deoxyribonucleic acid( DNA)is the germ plasm of the organism, owner of hereditary information and the material elements of gene expression, which is also called deoxygenize nucleic acid, and DNA can form the inherited mandate in order to guide the biological upgrowth and function, just as"blueprint"or"recipe", DNA plays a vary important part in the natural being movement (biology growth, development and reproduce) and abnormity being movement (cancerous breakand cancerous movement). The quantitative analysis, differential identification of DNA plays a good part in the genomy, virus and molecule biology. DNA is the most useful probe, but because the inner fluorescence of DNA is very weak, so the determination of DNA comes in for restricting using fluorescence of DNA directly. Ethidium bromide (EB) is the pioneer fluorescence probe, it not only can be apllied in the quantitative and qualitative analysis of nucleic acid, but also can be used in the dynamics characteristic study of nucleic acid, but EB is a carcinogen, which limit its application, so people begin to search new fluorescence probe of DNA. Now, people have done lots of work, the synthesis and utilization of more sensitive probe, which at the same time can avoid background disturbance of biology fluorescence, is the searching hotpot.Some work on the basement of pioneer`s work and some evolvement on the DNA fluorescence probe are reported in this paper. This thesis consists of four sections as follows:First, according to the point of our research, an explanation was made, consist of the constitute and structural feature of DNA,the theorybasis of florescence light,the activity style between DNA and molecular probe,the style of fluorescence probe and the method of our research.Second, fluorescence,absorption and circular dichroism spectra have been used in the interactions of DNA and dyes such as chromeazurol S,methyl violet,methyl green,crystal violet and pyrocatechol violet, that are base on the pedestal of 1-((cyclohexa-2,5-dienylidene)(phenyl)methyl)benzene. We also compare the results with EB. In the five dyes above, the results are as follows: chromeazurol S and crystal violet show different effects from that of the methyl violet and methyl green on the fluorescence spectra characteristics. Increasing fluorescence is seen with chromeazurol S and crystal violet addition, whereas quenching fluoresence is observed for methyl violet and methyl green ions. The addition of chromeazurol S and methyl violet causes the quenching absorption of the DNA solution, while the addition of methyl green and pyrocatechol violet causes the increasing absorption to the DNA solution also causes the circular dichroism spectra to change. The agarose gel electrophoresis results suggest that only chromeazurol S and EB can give the same intensity when binding to DNA, which could conclude well that chromeazurol S would possibly take part of EB as DNA fluorescence probe.Third, the spectroscopy interactions between phenylfluorone and DNA, eosin B and DNA, ethidium bromide (EB) and DNA have been studied by UV-absorption, fluorescence, circular dichroism spectroscopy and agarose gel electrophoresis methods. When DNA exists, the fluorescence intensity of phenylfluorone,eosin B and EB come out with different increasing. The absorbance of UV spectra present a hypochromic effect when DNA concentration increasing. The CD spectra of DNA has a great change both in negative and positive spectra. In the agarose gel electrophoresis, the luminescence intensity of EB-DNA system is the same as phenylfluorone-DNA system and eosin B-DNA system, so in the quantitative determination of DNA, we could implore the phenylfluorone or eosin B rather than the EB, which offer us an important base of new reagent in the quantitative determination of DNA, which also afford us clue to search more sensitive probe of DNA.Fourth, the spectroscopy interactions between ST and DNA, chromotropic acid and DNA, ethidium bromide (EB) and DNA have been studied by UV-absorption, fluorescence, circular dichroism spectroscopy and agarose gel electrophoresis methods. When DNA exists, the fluorescence intensity increases distinctly. The absorbance of UV spectra present a hypochromic effect when DNA concentration increasing. The CD spectra of DNA has a great change in positive spectra,by the agarose gel electrophoresis, we can make sure that ST or chromotropic acid is able to replace EB as a kind of DNA Fluorescence Probe , which offer us an important base of new reagent in the quantitative determination of DNA, which also afford us clue to search more sensitive probe of DNA.