螺旋通道微流控PCR芯片连续自动扩增DNA片段的研究

研制了由内向外流动的螺旋通道微流控PCR玻璃芯片,减少了PCR反应液在微通道中流动时的分散和阻力;讨论了扩增循环数和进样速度对长片段基因扩增的影响,在26min内成功扩增了质量浓度仅为10ng/mL的6012bpλ-DNA;通过将小孔径石英毛细管作为顺序注射(SI)系统的连接管路,使其死体积降到0.30μL.实现了微升级样品的自动换样、连续PCR扩增和微通道洗涤等功能.样品间无交叉污染.每小时可扩增500bpλ-DNA试样7个.扩增产物片段大小和荧光强度的相对标准偏差分别为0.4%和6.7%.

Automatic Continuously Amplification of Long Fragments DNA with Spiral Flow Through PCR Microchip

A spiral-channel flow-through PCR microchip reactor with 35 cycles, which reduced the dispersion and flow resistance of reaction solution, has been developed. A PCR amplification of a 6 012 bp-base pair fragment from λ-DNA was successfully performed on the chip in26 min, which is much faster than the reaction time(3 h) with conventional PCR. By transporting the solutions through the capillary instead of PTFE tubing, the dead volume of the sequential injection(SI) system was reduced from 14 to 0.30 μL. The SI system is capable of automatic manipulation of microliter samples in the PCR system, including continuous PCR amplification, autosampling and microchannel washing. Seven samples could be continuously amplified in 1 h and no cross-contamination between samples in serial treatments was observed. The standard deviations of the amplified fragment sizes and peaks area analyzed by a microfluidic chip-based capillary electrophoresis system, for replicates number 7, were 0.4% and 6.7%, respectively.