Name: 作者聚焦：呼吸道病毒多重检测的进展
Uploaded: 2023-11-10T14:50:00
Description: Watch this Scientific Journal Video about Advancements in Multiplex Detection of Respiratory Viruses at JoVE.com

这项工作得到了阿卜杜拉国王科技大学（King Abdullah University of Science and Technology）通过核心资金和S.M.H.的国家学期大挑战（NTGC）的支持。

1. Taq聚合酶的表达和纯化
<ol><li>在酶的C末端构建具有可切割的六组氨酸标签的质粒。</li>
	<li>按照标准方案38将50ng表达载体转化为大肠杆菌BL21-（DE3）菌株。</li>
	<li>将转化的细胞接种在四个6L烧瓶中，每个烧瓶在37°C下装有2L2YT培养基肉汤，以170rpm振荡，直到OD 600为0.8或细胞数6.4×108 。</li>
	<li>用0.5mM异丙基-β-d-硫代吡喃半乳糖苷（IPTG）诱导Taq聚合酶?...

用于呼吸道病毒检测的多重 RT-qPCR 检测

由于SARS-CoV-2、甲型/乙型流感和中东呼吸综合征冠状病毒变异株等常见呼吸道病毒的传播，感染率和死亡率高，给全球医疗系统带来了沉重的经济负担12,19,20。出于减轻这种负担的责任感，我们意识到需要一种快速、精确和可及的诊断检测方法，例如 RT-qPCR，以在一次测试中区分这些常见病毒。由于qRT-PCR的多重特性，诊断和区?...

正在进行的 2019 年冠状病毒病 （COVID-19） 的大流行是由称为严重急性呼吸系统综合症冠状病毒 2 （SARS-CoV-2）1 的新型冠状病毒引起的。由于 SAR-CoV-2 具有很强的传染性和快速传播能力，COVID-19 大流行出现在中国武汉市，并迅速蔓延到世界各地。这最终导致呼吸窘迫体征的开始，甚至死亡2,3,4。COVID-19 已在超过 213 个国家/地区被宣布为大流行，预计确诊病例数量将急剧增加，不同研究发表的论文证明了这一点 3,5.COVID-19主要通过感染者释放到环境中的小呼吸道飞沫传播，然后通过吸入或密切接触受污染的表面暴露给脆弱个体。当这些飞沫接触到眼睛、嘴巴或鼻子的粘膜时，一个人可能会被感染6.世界卫生组织（WHO）公布的统计数据显示，全球新冠肺炎确诊病例已超过7600万例，死亡人数达到惊人的700万例7。因此，联合国将 COVID-19 疾病引起的大流行归类为灾难，因为它对全球数十亿人的生活产生直接影响，并产生深远的经济、环境和社会影响。
包括彻底检测、早期发现、接触者追踪和病例隔离在内的公共卫生举措都已被证明对控制这一大流行至关重要8,9,10,11。冬季将增加其他呼吸道病毒的传播，如甲型和乙型流感，并伴有类似 COVID-19 的症状，因此难以及早识别、追踪和隔离 COVID-19 实例。每年，甲型和乙型流感的爆发始于深秋或一月初，季节性可预测12.SARS-CoV-2 和流感病毒具有许多流行病学特征。此外，在易感人群中也有相似之处，包括儿童、老年人、免疫功能低下以及患有慢性合并症（如哮喘、慢性阻塞性肺病、心肾衰竭或糖尿病）的个体12,13。这些病毒不仅具有易感人群，而且具有接触途径和呼吸道飞沫的传播途径14。预计随着流感季节接近 14，患者可能会感染不止一种呼吸道病毒。为此，需要在隔离有症状的患者之前对 SARS-CoV-2 和流感病毒进行筛查。由于全球缺乏核酸提取和诊断资源，无法对三种病毒（SARS-CoV-2、甲型流感和乙型流感）进行单独检测。为了在一次反应中筛选它们，需要开发一种方法或测试。
中东呼吸综合征（MERS）-CoV是人类冠状病毒（CoV）家族的成员。第一批中东呼吸综合征冠状病毒分离株来自沙特阿拉伯的一名住院患者，该患者于2012年9月因急性呼吸道疾病死亡15。有证据表明，中东呼吸综合征冠状病毒的主要宿主是单峰骆驼。已经证明，来自受感染的单峰骆驼的病毒是人畜共患的，因此可以感染人类16,17。感染这种病毒的人可以通过密切接触将其传播给他人18.截至2018年1月26日，全球已有2143例中东呼吸综合征冠状病毒感染实验室确诊病例，包括750例死亡19。中东呼吸综合征冠状病毒最典型的症状是咳嗽、发烧和呼吸急促。据报告，中东呼吸综合征冠状病毒感染还表现出肺炎、腹泻和胃肠道疾病症状20。目前尚无针对中东呼吸综合征冠状病毒的商业疫苗或特定治疗方法。因此，及时和准确的诊断对于预防中东呼吸综合征冠状病毒大范围暴发和区分中东呼吸综合征冠状病毒与SARS-CoV-2疾病至关重要。
迄今为止，已经提出了许多方法来检测这些病毒，例如多重 RT-PCR21、22、23、24、25、CRISPR/Cas1226、27、CRISPR/Cas928 和 CRISPR/Cas329、侧向层免疫测定30、纸质生物分子传感器31、一锅 SHERLOCK 测试32、DNA 适配体33、环介导的等温放大（LAMP）19,34等上述每种方法在灵敏度和特异性方面都有独特的优点和缺点。在这些方法中，基于核酸扩增的检测：多重qRT-PCR是最常见的，被认为是诊断SARS-CoV-2、甲型流感、乙型流感和MERS-CoV的金标准。
在这项研究中，我们设计并评估了各种引物组合和探针，以利用标准扭曲合成病毒 RNA 有效、准确和同时检测 SARS-CoV-2、甲型流感、乙型流感和 SARS-CoV-2、MERS-CoV。世界卫生组织 （WHO） 推荐针对 MERS-CoV 或 SARS-CoV-2 靶基因开发的多重检测方法。这些基因通常编码有助于形成复制/转录复合物 （RTC）35 的蛋白质和复合物，例如用于 MERS-CoV 检测的开放阅读框 1a （ORF1a） 内的区域。此外，结构蛋白由诊断测定中使用的基因编码，例如包膜基因 （upE） 和核衣壳基因 （N） 的上游区域，它们分别用于 MERS-CoV 和 SARS-Cov-2 测定35,36。我们使用内部的 R3T 一步法 RT-qPCR 试剂盒建立了用于检测病毒的 RT-qPCR37。使用标准扭曲合成RNA的10倍连续稀释液测试和评估我们的R3T一步法RT-qPCR试剂盒和引物组的病毒检测、灵敏度、特异性和动态范围。最低实际检测限为每次反应约10个转录本拷贝。因此，内部 R3T 一步法 RT-qPCR 试剂盒和引物/探针组可以成功用于 SARS-CoV-2、甲型流感、乙型流感和 SARS-CoV-2、MERS-CoV 的常规同时诊断。

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>0.45 &#956;m filter cups</td>
			<td>Thermo Scientific</td>
			<td>291-4545</td>
			<td></td>
		</tr>
		<tr>
			<td>10X Tris-Glycine SDS running buffer</td>
			<td>Novex</td>
			<td>LC2675</td>
			<td></td>
		</tr>
		<tr>
			<td>6-well tissue culturing plates</td>
			<td>Corning</td>
			<td>353046</td>
			<td></td>
		</tr>
		<tr>
			<td>Ammonium sulfate</td>
			<td>Fisher Scientific</td>
			<td>A701-3</td>
			<td></td>
		</tr>
		<tr>
			<td>Ampicillin</td>
			<td>Corning</td>
			<td>61-238-RH</td>
			<td></td>
		</tr>
		<tr>
			<td>Cation exchange (HiTrap SP HP) 5 mL</td>
			<td>Cytiva</td>
			<td>17-1152-01</td>
			<td></td>
		</tr>
		<tr>
			<td>D-(+)-Biotin, 98+%</td>
			<td>Thermo Scientific</td>
			<td>A14207.60</td>
			<td></td>
		</tr>
		<tr>
			<td>DH10Bac competent cells</td>
			<td>Fisher Scientific</td>
			<td>10361012</td>
			<td></td>
		</tr>
		<tr>
			<td>Dialysis bag (Snakeskin 10,000 MWC)</td>
			<td>Thermo Scientific</td>
			<td>68100</td>
			<td></td>
		</tr>
		<tr>
			<td>Dithiothreitol (DTT)</td>
			<td>Thermo Scientific</td>
			<td>R0862</td>
			<td></td>
		</tr>
		<tr>
			<td>Dnase/Rnase Free Distilled Water</td>
			<td>Ambion</td>
			<td>AM9930</td>
			<td></td>
		</tr>
		<tr>
			<td>dNTPs</td>
			<td>Thermo Scientific</td>
			<td>R0192</td>
			<td></td>
		</tr>
		<tr>
			<td>E. coli BL21(DE3) competent cells</td>
			<td>Invitrogen</td>
			<td>C600003</td>
			<td></td>
		</tr>
		<tr>
			<td>EDTA</td>
			<td>Fisher Scientific</td>
			<td>BP120-1</td>
			<td></td>
		</tr>
		<tr>
			<td>Elution Buffer</td>
			<td>Qiagen</td>
			<td>19086</td>
			<td></td>
		</tr>
		<tr>
			<td>ESF 921 insect cell culture medium (Insect cells media)</td>
			<td>Expression Systems</td>
			<td>96-001-01</td>
			<td></td>
		</tr>
		<tr>
			<td>FBS Solution</td>
			<td>Gibco</td>
			<td>A38400-01</td>
			<td></td>
		</tr>
		<tr>
			<td>Fugene (transfection reagent)</td>
			<td>Promega</td>
			<td>E2311</td>
			<td></td>
		</tr>
		<tr>
			<td>Gentamicin</td>
			<td>Fisher Scientific</td>
			<td>15750060</td>
			<td></td>
		</tr>
		<tr>
			<td>Glycerol</td>
			<td>Sigma Aldrich</td>
			<td>G5516-500</td>
			<td></td>
		</tr>
		<tr>
			<td>IGEPAL CA-630</td>
			<td>Sigma Aldrich</td>
			<td>I8896-100ml</td>
			<td></td>
		</tr>
		<tr>
			<td>Imidazole</td>
			<td>Sigma Aldrich</td>
			<td>56750-1Kg</td>
			<td></td>
		</tr>
		<tr>
			<td>Influenza A (H1N1) synthetic RNA</td>
			<td>Twist Bioscience</td>
			<td>103001</td>
			<td></td>
		</tr>
		<tr>
			<td>Influenza A (H3N2)&#160; synthetic RNA</td>
			<td>Twist Bioscience</td>
			<td>103002</td>
			<td></td>
		</tr>
		<tr>
			<td>Influenza B synthetic RNA</td>
			<td>Twist Bioscience</td>
			<td>103003</td>
			<td></td>
		</tr>
		<tr>
			<td>IPTG</td>
			<td>Gold Biotechnology</td>
			<td>I3481C100</td>
			<td></td>
		</tr>
		<tr>
			<td>Kanamycin</td>
			<td>Gibco</td>
			<td>11815-032</td>
			<td></td>
		</tr>
		<tr>
			<td>LB Agar</td>
			<td>Fisher Scientific</td>
			<td>BP1425-500</td>
			<td></td>
		</tr>
		<tr>
			<td>LB Broth media</td>
			<td>Fisher Scientific</td>
			<td>BP1426-500</td>
			<td></td>
		</tr>
		<tr>
			<td>Lysozyme</td>
			<td>Sigma Aldrich</td>
			<td>L6876-10G</td>
			<td></td>
		</tr>
		<tr>
			<td>Magnesium Chloride</td>
			<td>Sigma Aldrich</td>
			<td>13152-1Kg</td>
			<td></td>
		</tr>
		<tr>
			<td>MERS-CoV synthetic RNA</td>
			<td>Twist Bioscience</td>
			<td>103015</td>
			<td></td>
		</tr>
		<tr>
			<td>MicroAmp Fast Optical 96-well Reaction plates with Barcode (0.1 mL)</td>
			<td>Applied Biosystems</td>
			<td>10310855</td>
			<td></td>
		</tr>
		<tr>
			<td>Mini- PROTEAN TGX Precast Gel</td>
			<td>Bio-Rad</td>
			<td>456-1093</td>
			<td></td>
		</tr>
		<tr>
			<td>Miniprep kit</td>
			<td>Qiagen</td>
			<td>27106</td>
			<td></td>
		</tr>
		<tr>
			<td>Ni-NTA Excel (HisTrap Excel) 5 mL</td>
			<td>Cytiva</td>
			<td>17-3712-06</td>
			<td></td>
		</tr>
		<tr>
			<td>Ni-NTA HP (HisTrap HP) 5 mL</td>
			<td>Cytiva</td>
			<td>17-5248-02</td>
			<td></td>
		</tr>
		<tr>
			<td>Optical Adhesice Covers (PCR Compatible,DNA/Rnase/PCR Inhibitors Free</td>
			<td>Applied Biosystems</td>
			<td>4311971</td>
			<td></td>
		</tr>
		<tr>
			<td>Potassium Chloride</td>
			<td>Fisher Bioreagents</td>
			<td>BP366-1</td>
			<td></td>
		</tr>
		<tr>
			<td>Primers and Probes</td>
			<td>Integrated DNA Technologies, Inc.</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Protease Inhibitor Mini tablets EDTA-Free</td>
			<td>Thermo Scientific</td>
			<td>A32955</td>
			<td></td>
		</tr>
		<tr>
			<td>Protein marker</td>
			<td>Fermentas</td>
			<td>26616</td>
			<td></td>
		</tr>
		<tr>
			<td>RT-qPCR machine (QuantStudio 7 Flex)</td>
			<td>Applied Biosystems</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>S.O.C medium</td>
			<td>Fisher Scientific</td>
			<td>15544034</td>
			<td></td>
		</tr>
		<tr>
			<td>SARS-CoV-+A2:C442 synthetic RNA</td>
			<td>Twist Bioscience</td>
			<td>102024</td>
			<td></td>
		</tr>
		<tr>
			<td>Sf9 insect cells</td>
			<td>Gibco</td>
			<td>A35243</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium Chloride</td>
			<td>Sigma Aldrich</td>
			<td>S3014-1Kg</td>
			<td></td>
		</tr>
		<tr>
			<td>StrepTrap XT 5 mL</td>
			<td>Cytiva</td>
			<td>29401323</td>
			<td></td>
		</tr>
		<tr>
			<td>Tetracycline</td>
			<td>IBI Scientific</td>
			<td>IB02200</td>
			<td></td>
		</tr>
		<tr>
			<td>Tris Base Molecular Biology Grade</td>
			<td>Promega</td>
			<td>H5135</td>
			<td></td>
		</tr>
		<tr>
			<td>Tris-HCl</td>
			<td>Affymetrix</td>
			<td>22676</td>
			<td></td>
		</tr>
		<tr>
			<td>Tween 20</td>
			<td>Sigma Aldrich</td>
			<td>P1379-100ml</td>
			<td></td>
		</tr>
		<tr>
			<td>X-Gal</td>
			<td>Invitrogen</td>
			<td>B1690</td>
			<td></td>
		</tr>
	</tbody>
</table>

development of multiplex real-time rt-qpcr assays for the detection of sars-cov-2, influenza a/b, and mers-cov

导致 2019 冠状病毒病 （COVID-19） 的严重急性呼吸系统综合症冠状病毒 2 （SARS-CoV-2） 对公众健康构成严重威胁。在流感季节，SARS-CoV-2和其他呼吸道病毒的传播可能导致全人群难以控制的呼吸道疾病负担。为此，在即将到来的秋冬季节，需要仔细监测呼吸道病毒SARS-CoV-2、甲型流感、乙型流感和中东呼吸综合征（MERS-CoV），特别是在SARS-CoV-2、甲型流感和乙型流感的情况下，它们具有相似的流行病学因素，如易感人群、传播方式和临床综合征。如果没有靶标特异性检测，由于这些病毒的相似性，区分这些病毒的病例可能具有挑战性。因此，一种灵敏且有针对性的多重检测方法可以很容易地区分这些病毒靶标，这对医疗保健从业者很有用。在这项研究中，我们利用内部开发的 R3T 一步法 RT-qPCR 试剂盒开发了一种基于实时逆转录酶 PCR 的检测方法，用于同时检测 SARS-CoV-2、甲型流感、乙型流感和 SARS-CoV-2、MERS-CoV。只需 10 个拷贝的合成 RNA，我们就可以以 100% 的特异性同时成功识别 SARS-CoV-2、甲型流感、乙型流感和 MERS-CoV 靶标。该测定被发现是准确、可靠、简单、灵敏和特异性的。所开发的方法可用作医院、医疗中心和诊断实验室中优化的 SARS-CoV-2、甲型流感、乙型流感和 SARS-CoV-2、MERS-CoV 诊断检测以及研究目的。

The pandemic of the ongoing coronavirus disease 2019 (COVID-19) is caused by the novel coronavirus known as the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)1. Due to SAR-CoV-2&#39;s strong contagiousness and capacity for rapid transmission, the COVID-19 pandemic emerged in Wuhan City, China, and spread quickly throughout the world. This eventually led to the start of respiratory distress signs and even death2,3,4. COVID-19 has been declared a pandemic in more than 213 countries, expecting a steep increase in the number of confirmed cases, as evidenced by the papers published by different research studies3,5. COVID-19 is transmitted primarily by small respiratory droplets that infected individuals release into the environment and then get exposed to vulnerable individuals through inhalation or close contact with contaminated surfaces. When these droplets come into contact with the mucosa of the eyes, mouth, or nose, a person may become infected6. Statistics released by the World Health Organization (WHO) show that there have been more than 76 million confirmed cases of the pandemic worldwide, with a staggering 7 million deaths7. Thus, the United Nations classified the pandemic caused by COVID-19 disease as a disaster because of its direct impact on the lives of billions of people around the globe and had far-reaching economic, environmental, and social effects.
Public health initiatives including thorough testing, early detection, contact tracing, and case isolation have all been shown to be crucial in keeping this pandemic under control8,9,10,11. The winter months will increase the circulation of other respiratory viruses like Influenza A and B with COVID-19-like symptoms making it difficult to identify, track down, and isolate COVID-19 instances early on. Every year, Influenza A and B outbreak starts in the late fall or early January with a predictable seasonality12. Numerous epidemiological traits are shared by SARS-CoV-2 and Influenza viruses. Besides, sharing similarities in the susceptible populations which include children, the elderly, immunocompromised, and individuals with chronic comorbidities such as asthma, chronic obstructive pulmonary disease, cardiac and renal failure, or diabetes12,13. These viruses not only share vulnerable populations but also transmission routes of contact and respiratory droplets14. It is anticipated that patients may likely contract more than one of these respiratory viruses as flu season approaches14. For that, the screening of SARS-CoV-2 and the Influenza viruses needs to be done on symptomatic patients before they are isolated. Running separate tests for the three viruses (SARS-CoV-2, Influenza A, and Influenza B) is not possible due to the global lack of resources for nucleic acid extraction and diagnostics. In order to screen them all in one reaction, a method or test needs to be developed.
Middle East respiratory syndrome (MERS)-CoV is a human coronavirus (CoV) family member. The first MERS-CoV virus isolates came from a hospitalized patient in Saudi Arabia who had died in September 2012 due to acute respiratory issues15. There is evidence that suggests that a prominent reservoir host for MERS-CoV is dromedary camels. It has been proven that viruses from infected dromedary camels are zoonotic and thus can infect humans16,17. Humans infected with this virus can spread it to others through close contact18. As of January 26th,&#160;2018, there had been 2143 laboratory-confirmed cases of MERS-CoV infection including 750 deaths globally19. The most typical MERS-CoV symptoms are coughing, fever, and shortness of breath. MERS-CoV infections have also been reported to exhibit pneumonia, diarrhea and gastrointestinal sickness symptoms20. Currently, no commercial vaccine or specific treatment for MERS-CoV is available. Therefore, prompt and precise diagnosis is essential for preventing the widespread MERS-CoV outbreaks and differentiating MERS-CoV from SARS-CoV-2 disease.
To date, many approaches have been proposed to detect these viruses such as multiplex RT-PCR21,22,23,24,25, CRISPR/Cas1226,27, CRISPR/Cas928, and CRISPR/Cas329, lateral flow immunoassay30, paper-based biomolecular sensors31, SHERLOCK testing in one pot32, DNA aptamer33, loop-mediated isothermal amplification (LAMP)19,34, etc. Each of the aforementioned methods has unique benefits and drawbacks in terms of sensitivity and specificity. Among these methods, the nucleic acid amplification-based test: multiplex qRT-PCR, is the most common and is considered to be the gold standard for the diagnosis of SARS-CoV-2, Influenza A, Influenza B, and MERS-CoV.
In this study, we designed and assessed various primer combinations and probes for the effective, accurate, and simultaneous detection of SARS-CoV-2, Influenza A, Influenza B, and SARS-CoV-2, MERS-CoV utilizing standard twist synthetic viral RNAs. The multiplexed assays developed for either MERS-CoV or SARS-CoV-2 target genes are recommended by the World Health Organization (WHO). These genes generally encode proteins and complexes that contribute to the formation of a replication/transcription complex (RTC)35 such as the region within the open reading frame 1a (ORF1a) that is used for MERS-CoV assay. In addition, structural proteins are encoded by the genes utilized in diagnostic assays such as the upstream region of envelope gene (upE) and nucleocapsid gene (N) which are used for MERS-CoV and SARS-Cov-2 assays, respectively35,36. We used in-house R3T one-step RT-qPCR kit to establish the RT-qPCR for the detection of viruses37. Virus detection, sensitivity, specificity, and dynamic range of our R3T one-step RT-qPCR kit and primer sets were tested and evaluated using 10-fold serial dilutions of the standard twist synthetic RNAs. The lowest practical detection limit was approximately 10 transcripts copies per reaction. As a result, the in-house R3T one-step RT-qPCR kit and primer/probe sets can be successfully used and implemented for routine simultaneous diagnosis of SARS-CoV-2, Influenza A, Influenza B, and SARS-CoV-2, MERS-CoV.

作者聚焦：呼吸道病毒多重检测的进展 

开发用于检测SARS-CoV-2、甲型/乙型流感和MERS-CoV的多重实时RT-qPCR检测

近年来，使用PCR方法检测常见呼吸道病毒的诊断方法取得了重大进展21,22,23,24,25。然而，尽管取得了这些进步，但允许在一次测试中检测多种病毒的多重方法尚未得到广泛实施，特别是在RT-qPCR平台中。该方法已使用合成RNA病毒和反应组分的内部优化成功实现37</s...

Watch this Scientific Journal Video about Advancements in Multiplex Detection of Respiratory Viruses at JoVE.com

我们推出了两种基于探针的内部一步法RT-qPCR试剂盒，用于常见呼吸道病毒。第一种检测是针对 SARS-CoV-2 （N）、甲型流感（H1N1 和 H3N2）和乙型流感。第二种是SARS-Cov-2（N）和MERS（UpE和ORF1a）。这些检测可以在任何专业实验室中成功实施。

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes Coronavirus disease 2019 (COVID-19) is a serious threat to the general ...

development-multiplex-real-time-rt-qpcr-assays-for-detection-sars-cov

Research

JoVE Journal

Biology

Development of Multiplex Real-Time RT-qPCR Assays for the Detection of SARS-CoV-2, Influenza A/B, and MERS-CoV

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes Coronavirus disease 2019 (COVID-19) is a serious threat to the general public&#39;s health. During influenza seasons, the spread of SARS-CoV-2 and other respiratory viruses may cause a population-wide burden of respiratory disease that is difficult to manage. For that, the respiratory viruses SARS-CoV-2, Influenza A, Influenza B, and Middle East respiratory syndrome (MERS-CoV) will need to be carefully watched over in the upcoming fall and winter seasons, particularly in the case of SARS-CoV-2, Influenza A, and Influenza B, which share similar epidemiological factors like susceptible populations, mode of transmission, and clinical syndromes. Without target-specific assays, it can be challenging to differentiate among cases of these viruses owing to their similarities. Accordingly, a sensitive and targeted multiplex assay that can easily differentiate between these viral targets will be useful for healthcare practitioners. In this study, we developed a real-time reverse transcriptase-PCR-based assay utilizing an in-house developed R3T one-step RT-qPCR kit for simultaneous detection of SARS-CoV-2, Influenza A, Influenza B, and SARS-CoV-2, MERS-CoV. With as few as 10 copies of their synthetic RNAs, we can successfully identify SARS-CoV-2, Influenza A, Influenza B, and MERS-CoV targets simultaneously with 100% specificity. This assay is found to be accurate, reliable, simple, sensitive, and specific. The developed method can be used as an optimized SARS-CoV-2, Influenza A, Influenza B, and SARS-CoV-2, MERS-CoV diagnostic assay in hospitals, medical centers, and diagnostic laboratories as well as for research purposes.

We present two probe-based in-house one-step RT-qPCR kits for common respiratory viruses. The first assay is for SARS-CoV-2 (N), Influenza A (H1N1 and H3N2), and Influenza B. The second is for SARS-Cov-2 (N) and MERS (UpE and ORF1a). These assays can be successfully implemented in any specialized laboratory.

科研

生物学

Preparation and Testing of Multiplex R3T One-Step RT-qPCR Kit Components

To begin, prepare the 2X buffer for RT-qPCR in DNase/RNase free water. Store the buffer at minus 20 degrees Celsius until further use. Next, mix the primers and the probes in a 1.5 milliliter tube.Make up the volume with elution buffer. Then store the tube at minus 20 degrees Celsius. Prepare an enzyme mix with Taq polymerase and M-MLV RT in a 1.5 milliliter tube on ice.Make up the volume with Taq polymerase storage buffer. Now re-suspend the viral synthetic RNAs in separate tubes with 100 microliters of Tris-EDTA buffer to make stocks of 10 to the sixth RNA copies per microliter. To mix the virus stocks, add five microliters each of SARS-CoV-2 influenza A and B to 50 microliters of Tris-EDTA buffer.Similarly, mix SARS-CoV-2 and MERS-CoV to obtain a second viral mix. Dilute both mixtures tenfold to obtain a final dilution of 10 RNA copies per microliter. To each well of a 96-well plate, pipette 2X buffer, primer, enzyme, DNase/RNase free water, and the corresponding RNA mixtures.Seal the plate with an adhesive plate seal. Then centrifuge the plate for one minute to collect the liquid at the well bottom. Next, program the PCR machine to accept the fast 96-well block type with the experimental type set to standard curve.Set the reagents to TaqMan reagents and select standard run properties. Define the gene targets and the reporter dye. Then define the sample names for each reaction to be tested and assign targets and samples to the plate layout.Now, input the cycle program into the instrument. Transfer the plate to the real-time qPCR machine in the correct orientation and press run to initiate the cycle. Choose the file location to save the experimental data.Then examine the amplification plots provided by the qPCR program. The two developed kits were able to successfully amplify all three target genes simultaneously with as low as 10 RNA copies per reaction. The amplification efficiencies for all viral titrations were above 99%