Integrated reaction system based on W/O emulsion in microchannel

在本研究计画中，我们一直致力于开发以连续油相液滴处理为基础的微反应器系统。在这个系统中，这些液滴起到了极其微型化的反应器的作用。为了建立微反应器的操作技术，我们研究了液滴的产生和分离方法，以及用于微通道中液滴处理的电动微泵系统。首先，我们研究了电喷雾液滴的形成，并通过向微型电极施加交流高压成功地分离了液滴。在此基础上，研制了一种基于激光辐照和交流电场协同作用的微泵系统。作为乳化反应器的一个重要应用，我们将油包水型乳化液应用于PCR反应中。这种乳化PCR允许扩增单分子DNA和RNA。然而，当通过搅拌进行乳化时，难以排除污染的可能性。特别是单分子PCR，污染是一个严重的问题。我们还开发了一种新的基于电场应用的乳化系统。在该系统中，我们成功地通过施加电场的管外电极的乳化。该方法可减少污染的可能性，并可应用于单分子PCR的W/O乳液体系。

In this research project, we have been engaged in development of micro-reactor system based on droplets handling in continuous oil phase. In this system, those droplets function as extremely miniaturized reactors. In order to establish handling technique of the micro-reactors, we investigated methods to production and division of droplets, and also electric micro-pump system to handle droplets in micro-channel.First of all, we examined droplet formation by electro-spray, and succeeded in division of droplets by applying AC high voltage to miniaturized electrodes. Furthermore, we developed a micro-pump system based on synergetic effects of laser irradiation and AC electric field application. Because this pump lacks movable part, it can be miniaturized easily.As an important application of emulsified reactors, we applied water-in-oil emulsion to PCR. This emulsified PCR permitted amplification of both single molecule DNA and RNA. However, when emulsification is carried out by stirring, it is hard to exclude possibility of contamination. Especially single molecule PCR, contamination is a serious problem. We also developed a new emulsification system based on electric field application. In this system, we succeeded in emulsification by applying electric field by electrodes outside of tubes. This method can reduce possibility of contamination and permit application to W/O emulsion system for single molecule PCR.