采用含RNA反转录(Reverse transcription,RT)和在线荧光分析的连续流动聚合酶链式反应(Poly-merase chain reaction,PCR)微流控技术检测食源致病性轮状病毒。此RT-PCR微流控装置以加热铜块组成恒温带,以聚四氟乙烯毛细管微通道为反应体系构建而成。采用循环水冷却退火区,此装置能获得低至31℃的退火温度,而且温度控制及其稳定性良好,因而能满足不同PCR的要求。为了充分体现PCR微流控技术的优越性,在线荧光分析被用于检测PCR产物。当流速为7.5 mm/s时,轮状病毒RNA的cDNA扩增和在线荧光分析能在约12 min完成(扩增约10 min,在线分析约2 min)。在此集成化的RT-PCR微流控装置上,1 h可完成轮状病毒RNA的RT-PCR以及其扩增产物的在线荧光分析,样品检出限达到6.4×104 copies/μL。
A continuous-flow polymerase chain reaction(PCR) microfluidics integrated with reverse transcription(RT) of RNA and online fluorescence analysis has been introduced,which has been successfully applied for fast amplification and identification of foodborne pathogenic Rotavirus.On this continuous-flow RT-PCR device,the isothermal heating copper blocks provides the temperatures for RT-PCR,and the polytetrafluoroethylene(PTFE) capillary was used as the RT-PCR reaction channel.By using the cycling water to cool the annealing zone,the annealing temperature as low as 31 ℃ could be obtained for the presented device,where good temperature control and stability was also achieved.Therefore,this device can meet different PCR requirements.To make the best of the advantages of microfluidic PCR,the online fluorescence analysis of amplification products has been performed.When the flow rate of 7.5 mm/s was used,the amplification of cDNA synthesized from Rotavirus RNA and then the online fluorescence analysis of amplification products could be completed in about 12 min(about 10 min for amplification and 2 min for analysis).By using this microfluidic device,the RT-PCR of Rotavirus RNA and the online fluorescence analysis of its products can be accomplished within 1 h or so,and as well the detection limit of the RNA concentration is 6.4×104 copies/μL.