多通道DNA测序仪的新型设计

Novel Design for Multi-Channel DNA Sequencing System

目前大多数商品化的DNA测序仪的信号检测系统是基于CCD或PMT。基于CCD的系统需要对CCD进行制冷,其造价相对较高且灵敏度相对较低;基于PMT的系统使用机械扫描来实现多通道检测,其工作稳定性相对较低且工作的机械噪音大。本文提出了新型的DNA测序仪,它采用PMT共焦荧光系统,通过f-θ透镜和光学扫描来实现多通道并行检测。在此新系统中采用标准双链DNA样品:pBR322/HaeIII(使用TO染料)进行了毛细管电泳实验,测得系统的检测限可达:1.1841×10-11mol/L。新型DNA测序仪的工作机械噪声相比基于机械扫描的系统要低得多,且工作稳定性和灵敏度也很高。此系统可应用于基于激光诱导荧光的毛细管阵列和多通道微芯片的电泳检测。

Today most commercial DNA sequencing systems＇ signal detection was based on CCD or PMT. The CCD based system needs cooled CCD, whose cost is high and the sensitivity is relatively low; The PMT based system using mechanical scanning to realize multi-channel detection, whose stability is relatively low and the working noise is high. In this paper, a novel multi-channel DNA sequencing system was presented, which was based on single PMT confocal fluorescence detection and optical scanning adopting an ftheta lens. Capillary electrophoresis experiments were executed in the system for DNA marker pBR322/Hae III. The system＇s limit of detection was evaluated to be 1.1841× 10-1 lmol/L （dsDNA with Thiazole Orange）. Its working noise is much lower compared with that based on mechanical scanning one, and the stability and detecting sensitivity is high. The system is expected to be applied to both capillary array and multi-channel microchip electrophoresis detection based on laser-induced fluorescence.