| Popis: |
Single molecule fluorescence microscopy is a powerful tool to investigate local environments at the nanometer scale. Oxidation of DNA is an important problem that leads to DNA mutations. In this project, single molecule fluorescence measurements were used to study the interaction between covalently bound nucleotides (dNTP) and fluorophores (Cyanine dye), dNTP-Cy3 that have been incorporated into DNA. By tracing changes in the fluorescence signal, evidence for single events of DNA oxidation were found that could otherwise not be observed at the ensemble level. The differences between the nucleotides and their quenching properties are shown here especially guanine’s ability to temporarily quench the fluorescence of Cy3 completely. After some illumination time, the quenching of the dye by the guanine changes dramatically. We interpret this change to possible oxidation of the guanine base. This work could lead to a method for monitoring and investigating important DNA oxidation processes which are essential to Genomic and Cancer research. |
