摘要
为使电化学实时定量PCR仪能够满足PCR扩增过程对温度特性的要求,对普通PCR芯片进行了结构和材料方面的优化,设计了一种电化学实时定量多通道PCR芯片。利用有限元仿真软件ANSYS分析了PCR芯片温度特性,并提出了隔热和热补偿的措施来改善电化学实时定量PCR仪的热循环系统,通过仿真验证了方案的有效性。首先采用环形结构改善芯片各通道温度的一致性;同时针对电化学检测特点,采用由单晶硅片、铝片和聚碳酸酯组成的三层结构来减小芯片反应池的热迟滞性。其次,在该芯片有限元模型的基础上进行温度场仿真;先采用稳态分析方法确定隔热层厚度与热补偿温度来削弱芯片与外围空气的对流换热作用,以改善芯片的温度准确性与均匀性;再通过瞬态分析测试改善后热循环系统中芯片的热迟滞性和恒温性。改善后热循环系统的热分析结果为:芯片温度准确性与均匀性误差小于0.2℃,各通道温度一致性误差为0℃,试剂升降温速度分别为4℃/s和3℃/s。结果表明该热循环系统的温度特性能够满足PCR仪工作性能的要求。
In order to make the eletrochemical real-time quantitaive PCR instrument meet the requirements of temperature characterstics in the process of PCR amplification,some optimizations in structure and material of conventional PCR chip were made to fabricate a multi-channel electrochemical real-time quantitative PCR chip.By using finite element simulation software ANSYS,temperature characteristics of the PCR chip were analyzed.According to the analysis results,insulation and thermal compensation were used to improve the thermal cycle system for electrochemical real-time quantitative PCR instrument,which was proved effective in the simulation test.Annular structure was applied to improve the consistency of temperature among every channel of the chip.Meanwhile,considering the character of the electrochemical detection,the structure of three layers,consisting of mono-crystalline silicon,aluminum and polycarbonate,was adopted to reduce the thermal hysteresis of the chip＇s reaction pool.Then,we simulated the temperature field of the chip based on its finite element model.Through the steady-state analysis,the thicknesses of the insulation layers and the thermal compensation temperature were determined so as to weaken the heat transfer effect between the chip and the peripheral air,which could improve the accuracy and uniformity of the chip＇s temperature.Furthermore,the thermal hysteresis and homoiothermy of the chip were tested in the improved thermal cyde system through transient analysis.The thermal analysis results of the chip in the improved thermal cyde system were as follows.The uniformity and accuracy errors of the temperature was less than 0.2℃.The temperature consistency error was 0℃ among every channel of the chip.The ascending and cooling speeds were 4℃/s and 3℃/s,respectively.The facts indicated that the temperature characteristics of the thermal cyde system could meet the performance requirements of the PCR instrument well.
出处
《中国生物医学工程学报》
CAS
CSCD
北大核心
2011年第4期589-594,共6页
Chinese Journal of Biomedical Engineering
基金
福建省自然科学基金(2009J01281)
福建省科技计划重点项目(2009I0016)
国家大学生创新性实验计划(101038605)
关键词
温度特性
电化学实时定量
PCR芯片
有限元仿真
temperature characteristics
electrochemical real-time quantitative
PCR chip
finite element simulation
