Nanoparticle Effects Of Water-soluable Amino-modified CdSe/ZnS Quantum Dots On Polymerase Chain Reaction

Polymerase chain reaction (PCR) is an indispensable fundamental nucleic amplification technology in vitro in modern biology. Since being invented by American scientist Kary Mullis in 1983, it has bocome a powerful tool in scientific research and strongly promoted the development of life science. With the development of the technology, its improvement has never been stopped. Following many other attempts, nanomaterials were introduced into PCR to refine its performance recently.Quantum dots (QDs) is a class of quasi-zero-dimensional semiconductor material. It is concerned mainly due to its excellent optical property, while, its other properties, such as surface group property, are less concerned. The quantum dots could be modified by many reagents and different modifications make quantum dots different surface properties. Our group firstly introduces amino-modified quantum dots to PCR system to study its effects on PCR performance, which is not only a bold attempt of the application of quantum dots, but also an exploratory combination of biotechnology and nanotechnology.In this dissertation, we will elucidate the effects of the amino-modified CdSe/ZnS quantum dots as an additive on PCR performance and its underlying mechanism. This study includes two parts as following:1. To study the effects of amino-modified CdSe/ZnS quantum dots on PCR performanceThe evaluation of PCR performance is mainly with the help of the following parametres:specificity, sensitivity, efficiency, yield and fidelity. In the study, we introduce the quantum dots into the PCR amplification system with the target product of different lengths to evaluate the effects of the quantum dots on PCR specificity, sensitivity, efficiency and yield, applying different sorts of PCR technology, and evaluate the effect of quantum dots on PCR fidelity by rpsL fidelity assay. The results show that in the range of our research, PCR sensitivity, efficiency, yield and fidelity decrease to varying degrees with the addition of quantum dots. However, the effect of quantum dots on PCR performance is regardless of PCR specificity, and QDs just tend to preferentially inhibit the amplification of larger products. Moreover, although the fidelity decreases, the result of DNA sequence shows no change of product sequence.2. To explore the mechanism of the effects of amino-modified CdSe/ZnS quantum dots on PCR performanceIn the study, we explore the mechanism of the above phenomena by conventional PCR technology and agarose gel electrophoresis. The result shows that the quantum dots mainly take interaction with DNA polymerase in PCR reagents. Moreover, the quantum dots can interact with another kind of protein--bovine serum albumin (BSA), and BSA can reverse the inhibition on PCR caused by quantum dots. The reason of the reversal is that BSA interacts with quantum dots priorly compared with DNA polymerase in the case that the sample plus order and operation are nonnal.