Shuming Lecture Hall|COVID-19 Nucleic Acid DetectionPCRtechnology

&Nbsp;

Epidemic prevention and control

Scientific epidemic prevention measures are clearly available“core”

At present, Shanghai is at a critical stage of the prevention and control of the epidemic situation of novel coronavirus. In this smoke-free battlefield, the most effective and only way to prevent the wanton spread of COVID-19 is to screen COVID-19 infected people in a timely and rapid manner and isolate them in a timely manner.nucleic acid testIt is the most accurate, effective and low-cost technical way to screen COVID-19 infected people.

&Nbsp;

What isPCR?

polymerase chain reaction Polymerase Chain Reaction,for shortPCR,Also known as polymerase chain reaction, it is a method of utilizingDNAThe principle of double stranded replication is to replicate specific genes outside the organismDNAFragment nucleic acid synthesis technology. Through this technology, a large number of target genes can be amplified in a short period of time without relying on organisms such as Escherichia coli or yeast.

&Nbsp;

PCRThe Three Basic Steps of Amplification

（one）denaturation: TemplateDNAAfter heating to94 ℃After holding it for a certain period of time, based onDNAThe principle of semi reserved replication, as well as the principle of complementary base pairing, which involves double stranded DNA during the replication processDNAAble to break down the chain, changing from a double chain to a single chain, preparing for the next round of reaction;

（two）annealing: TemplateDNAAfter heating and denaturing into a single chain, the temperature drops to55 ℃Left and right, primers and templatesDNAPairing and binding of complementary sequences in a single strand;

（three）extend: The temperature rises again72 ℃Left and right, onDNAUnder the action of polymerase, freeDNTPAccording to the principle of complementary base pairing, it is combined onto a single chain to form a new double chain composed of old and new heterozygous chainsDNA.

PCRAmplification principle: deformation-annealing-Extended temperature cycle

&Nbsp;

In theory, after the above steps, the goalDNAThe concentration can be doubled. Repeat the above process to obtain more“Half reserved replication chain”The new chain formed can serve as a template for the next cycle. Each cycle needs to be completedtwo~fourMinutes, justtwo~threeYou can achieve your goal in just an hourDNA扩增放大几百万倍.

Fully automatic nucleic acid purification and real-time fluorescencePCRAnalysis system

&Nbsp;

经过以上分析，我们就可以理解为什么核酸检测结果最快能在几个小时内出结果.

Real time fluorescencePCRquantitative analysis      &Nbsp;

PCRTemperature control indicators of the amplifier主要有：温度的准确性、均匀性、以及升降温速度.

1.&Nbsp;Accuracy of temperatureThe consistency between the sample hole temperature and the set temperature is directly related to the success or failure of the experiment. Therefore, forPCR扩增仪而言温度控制就意味着产品质量.

2.&Nbsp;Uniformity of temperature：是指样品孔间的温度差异，它关系到在不同样品孔进行反应结果的一致性.

3.&Nbsp;Temperature rise and fall speedFaster temperature rise and fall speed can effectively shorten reaction time and possible non-specific binding and reaction time, thereby improvingPCR反应特异性.

&Nbsp;

相较于传统的相对稳定耐用的机械式，新的半导体温控technology——TEC温度控制technologyWith the advantage of faster temperature rise and fall, it has become aPCR扩增仪的首选温度控制技术.

&Nbsp;

Semiconductor coolerThermo Electric Cooler，for shortTEC)是利用半导体材料的帕尔贴效应制成的。如图下所示，帕尔帖效应是指当直流电流通过两种半导体材料组成的电偶时，其一端吸热，一端放热的现象.TECIncluding somePType andNType pairs (groups), which are connected together through electrodes and sandwiched between two ceramic electrodes, when there is current flowing from TECWhen flowing through, the heat generated by the current will shift from TECFrom one side to the other, on the TECUpper generation″heat″Lateral sum″cold″Side, this is TECHeating and cooling principles of.&Nbsp;

&Nbsp;

The Peltier effect,PNSection and Heat Flow Diagram

&Nbsp;

PCRAmplifiers generally haveTwo temperature control modesModule temperature control mode（Block control）Temperature control mode of reaction tube（Tube control）. The temperature of the sample inside the tube cannot reach the preset temperature simultaneously with the temperature control module, especiallyPCRThe incubation process in the reaction is generallythirtySeconds or less, if the module only temperature control mode is used, there will be a significant difference between the incubation time of the reaction mixture and the programmed time. In order to achieve precise temperature control inside the reaction tube, it is necessary toAdopting reaction tube control mode, parameter calibration and compensation are carried out through temperature control algorithm，确保反应混合物按照程序设定的时间维持预设温度.

&Nbsp;

Technology War“Epidemic”Shuming is in action

Faced with the rapid spread of Omicron in Hong Kong, Shenzhen, Shanghai and other places recently, the nucleic acid testing capability is facing great challenges in terms of quantity and speed. Suming Semiconductor has actively utilized its technological advantages and organized technical experts to conduct researchPCROptimization solutions for amplification technology toPower device gate driver chip andTECcontroller为着力点，优先保障芯片供应和交付，与客户一起助力抗疫，共克时艰.

&Nbsp;

Self-developed by Shuming Semiconductor20V-600VFull series of low side, half bridge, three-phase half bridge power transistor gate driver chips with voltage resistance（SLM2103S、SLM2136Etc.) can be used for drivingTECAssistancePCRExpansion instrument customers can quickly and conveniently complete system design, and in the current period of semiconductor supply shortage满足客户设计方案的快速变更、验证与量产.

600VSchematic diagram of the operation of the voltage resistant half bridge power device driver chip

600VSchematic diagram of the operation of the voltage withstand three-phase half bridge power device driver chip

&Nbsp;

Single chip of digital semiconductorTECController products——SLM8833/8834/8835IntegratedTECThe driving circuit, low-temperature drift high-precision temperature error amplifier and loop compensation circuit, temperature setting and sensing circuit adopt an efficient single inductor architecture to achieve more compact, higher conversion efficiency, and lower noise; The power stage integrates ultra-low impedanceMOSFETLower loss and longer lifespan; Simultaneous matching simulationPIDAnd numbersPIDTwo temperature control modes, withSatisfy customersPCRInnovative design requirements for miniaturization of amplification instruments.

&Nbsp;

fromSLM8834Constituent TECSystem Block Diagram

simulationPIDTemperature controller mode&Nbsp;

numberPIDTemperature mode

&Nbsp;