顺序注射-液芯波导-激光诱导荧光微流控电泳系统分析脱氧核糖核酸

A Sequential Injection-Liquid Core Waveguide-Laser Induced Fluorescence Microfluidic System for Deoxyribonucleic Acid Separation

报道了一种基于液芯波导的小型激光诱导荧光微流控分析系统及其在分离检测DNA样品中的应用。使用6 cm长Teflon AF涂覆的石英毛细管作为液芯波导管,同时作为电泳分离通道和荧光检测光路,将分离后样品的荧光信号传送到检测器。半导体激光器(LD)作为激发光源,产生的荧光信号在波导管出口收集。设计了一种特殊的出口储液池,直接使用滤光片作为液池的后壁并置于光电倍增管(PMT)窗口处,从而使全部检测系统仅由LD、LCW、滤光片和PMT四部件组成,达到了结构最简化。使用顺序注射(SI)系统实现了自动样品更新,该系统通过一种改进结构的可消除气泡的接口与微流控系统联接。采用这种联用系统实现了溴化乙锭(EB)标记的X174-HaeⅢ裂解液中11个脱氧核糖核酸片段的分离和聚合酶链反应扩增样品的检测。

A compact capillary electrophoresis （CE） system based on liquid-core waveguide （LCW） technique was developed for deoxyribonucleic acid （DNA） separations with laser induced detection. A Teflon AF coated silica capillary served as both the separation channel for CE separation and as an LCW for light transmission of fluorescence emission to the detector. A 532 nm green diode laser illuminated transversely through a 0.2 mm diameter optical fiber at the detection point on the LCW capillary without focusing, and fluorescence light was transmitted to the capillary outlet. To simplify the optics and enhance collection of light from the capillary outlet, an outlet reservoir was designed, with a high pass filter as light transmission window, positioned directly in front of a photomuhiplier tube. Automated sample introduction was achieved using a sequential injection system through a modified split-flow interface that allowed improved release of gas bubbles and showed improved stability. In the separation of a φX174-HaeⅢ digest sample, using ethidium bromide as labeling dye, all 11 fragments of the sample were effectively resolved. A polymerase chain reaciton product was also determined using the system under the same experimental conditions.