一种载样简单的多重可视化PCR微芯片

在核酸检测领域急需一种能够经济、快速、操作简便且同时检测多个靶标的新技术。常规多重PCR能够同时扩增多个靶标,但由于在一个试管中引物间的相互作用和竞争,重数往往受到限制。本研究设计了一种操作简单的多重PCR芯片,可以同时进行54个靶标的扩增。芯片结构简单,一条微通道将正下方平行排列的多个微孔连接在一起,微通道只留加样口和出样口。同时整个微通道呈疏水状态,微孔呈亲水状态。将不同的引物对和低溶点琼脂糖提前固定于不同的微孔中,通过一次加入PCR mix,并加入矿物油推动PCR mix进入到每个微腔室中,同时微孔也被矿物油相互隔离避免交叉反应。加样后将芯片放置于平板PCR仪上进行扩增,在整个反应过程中低溶点琼脂糖呈液态,反应结束后凝固成固体,便可引入核酸染料进行染色,最后利用自制小型的紫外照射仪上进行可视化检测和拍照记录。利用此平台成功实现了对7种非常重要和常用的转基因作物靶标的并行检测,结果显示此平台具有较高的灵活性和特异性。此技术经过进一步优化可应用于包括转基因检测在内的多重核酸检测领域。

A visual multiplex PCR microchip with easy sample loading

There is an urgent demand for affordable, rapid and easy-to-use technology to simultaneously detect many different DNA targets within one reaction. Conventional multiplex PCR is an effective methodology to simultaneously amplify different DNA targets. However, its multiplicity is limited due to the intrinsic interference and competition among primer pairs within one tube. Here, we present an easy multiplex PCR microchip system, which can simultaneously detect 54 targets. The design of the microchip is quite simple. There is a microchannel connected with multiple underlying parallel microwells. And every microchannel has an inlet/outlet for loading PCRmix. The surface of the microchannel is hydrophobic and the inner surface of the microwell is hydrophilic, which enables us to load and separate the PCRmix into different microwells simultaneously. Different primer pairs and low melting agarose are pre-fixed in different microwells, and the microchip is assembled with top glass. The PCRmix is loaded into inlets and then mineral oil is sequentially pipetted into channels to push the PCRmix into all microwells and subsequently mineral oil fills the channels to avoid cross contaminations. After the PCRmix is loaded, it would be placed on a plat thermal cycler for PCR. During PCR, the low melting gel in the well is liquid and after PCR it would be solidified due to temperature changes. When PCR is completed, a nucleic acid dye is introduced into channels and then results are visualized by a home-made, potable UV detector. In our platform we successfully detected seven frequently used targets of genetically modified (GM) organisms. The results demonstrate that our platform has high flexibility and specificity. Due to the excellent performance of this technology, we believe that it can be applied to multiple nucleic acid detection fields including GM organisms.