Foundation and Clinical Evaluation of a New Method for Detecting SARS-CoV-2 Antigen by Fluorescent Microsphere Immunochromatography

PurposeTo develop a rapid detection reagent for SARS-CoV-2 antigen for the auxiliary diagnosis of new coronary pneumonia (COVID-19), and perform the methodological evaluation and clinical evaluation of the reagent.MethodSARS-CoV-2 N-protein test strip was created by combining fluorescent microsphere labeling technology and immunochromatographic technology, based on the principle of double antibody sandwich. Then we evaluated the analytical capability and clinical application of the strips.ResultThe limit of detection of the strips for recombinant N protein was 100 ng/ml and for activated SARS -CoV-2 virus was 1 × 103 TCID50/ml. The strips also have high analytical specificity and anti-interference capability. According to the predetermined cut-off value, the specificity of the test strip in healthy controls and patients with other respiratory disease was 100.00 and 97.29%, the sensitivity in COVID-19 cases at progress stage and cured stage was 67.15 and 7.02%. The positive percentage agreement and negative percentage agreement of antigen strip to RNA test were 83.16 and 94.45%.ConclusionSARS-CoV-2 fluorescence immunochromatographic test strip can achieve fast, sensitive and accurate detection, which can meet the clinical requirements for rapid detection of viruses on the spot.

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Wearable Aiegens-Based Lateral Flow Test Strip for Rapid Detection of SARS-CoV-2 N Protein and BRD Protein

SSRN Electronic Journal ◽

10.2139/ssrn.3956662 ◽

2021 ◽

Author(s):

Guo-Qiang Zhang ◽

Zhiyuan Gao ◽

Jingtian Zhang ◽

Heqi Gao ◽

Ryan T. K. Kwok ◽

...

Keyword(s):

Rapid Detection ◽

Test Strip ◽

Lateral Flow ◽

N Protein ◽

Flow Test ◽

Lateral Flow Test

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Saliva as a testing specimen with or without pooling for SARS-CoV-2 detection by multiplex RT-PCR test

10.1101/2020.10.27.20219196 ◽

2020 ◽

Author(s):

Qing Sun ◽

Jonathan Li ◽

Hui Ren ◽

Larry Pastor ◽

Yulia Loginova ◽

...

Keyword(s):

Clinical Evaluation ◽

High Throughput ◽

Molecular Detection ◽

Limit Of Detection ◽

Saliva Sample ◽

Clinical Samples ◽

Rank Test ◽

Percentage Agreement ◽

Testing Specimen ◽

Significant Difference

AbstractBackgroundSensitive and high throughput molecular detection assays are essential during the coronavirus disease 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The vast majority of the SARS-CoV-2 molecular assays use nasopharyngeal swab (NPS) or oropharyngeal swab (OPS) specimens collected from suspected individuals. However, using NPS or OPS as specimens has apparent drawbacks, e.g. the collection procedures for NPS or OPS specimens can be uncomfortable to some people and may cause sneezing and coughing which in turn generate droplets and/or aerosol particles that are of risk to healthcare workers, requiring heavy use of personal protective equipment. There have been recent studies indicating that self-collected saliva specimens can be used for molecular detection of SARS-CoV-2 and provides more comfort and ease of use for the patient. Here we report the performance of QuantiVirus™ SARS-CoV-2 multiplex test using saliva as the testing specimens with or without pooling.MethodsDevelopment and validation studies were conducted following FDA-EUA and molecular assay validation guidelines. Using SeraCare Accuplex SARS-CoV-2 reference panel, the limit of detection (LOD) and clinical evaluation studies were performed with the QuantiVirus™ SARS-CoV-2 multiplex test. For clinical evaluation, 85 known positive and 90 known negative clinical NPS samples were tested. Additionally, twenty paired NPS and saliva samples collected from recovering COVID-19 patients were tested and the results were further compared to that of the Abbott m2000 SARS-CoV-2 PCR assay. Results of community collected 389 saliva samples for COVID-19 screening by QuantiVirus™ SARS-CoV-2 multiplex test were also obtained and analyzed. Moreover, saliva pooling with 6 and 12 samples together were also evaluated.ResultsThe LOD for the QuantiVirus™ SARS-CoV-2 multiplex test was confirmed to be 100-200 copies/mL. The clinical evaluation using contrived saliva samples indicated that the positive percentage agreement (PPA) of the QuantiVirus™ SARS-CoV-2 multiplex test is 100% at 1xLOD, 1.5xLOD and 2.5xLOD. No cross-reactivity was observed for the QuantiVirus™ SARS-CoV-2 multiplex test with common respiratory pathogens. Testing of clinical samples showed a positive percentage agreement (PPA) of 100% (95% CI: 94.6% to 100%) and a negative percentage agreement (NPA) of 98.9% (95% CI: 93.1% to 99.9%). QuantiVirus ™SARS CoV-2 multiplex test had 80% concordance rate and no significant difference (p=0.13) in paired saliva and NPS specimens by Wilcoxon matched pairs signed rank test. Positive test rate was 1.79% for 389 saliva specimens collected from the communities for COVID-19 screening. Preliminary data showed that saliva sample pooling up to 6 samples for SARS-CoV-2 detection is feasible (sensitivity 94.8% and specificity 100%).ConclusionThe studies demonstrated that the QuantiVirus™ SARS-CoV-2 multiplex test has a LOD of 200 copies/mL in contrived saliva samples. The clinical performance of saliva-based testing is comparable to that of NPS-based testing. Pooling of saliva specimens for SARS-CoV-2 detection is feasible. Saliva based and high-throughput QuantiVirus™SARS-CoV-2 multiplex test offers a highly desirable test during the ongoing COVID-19 pandemic.

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Wearable AIEgen-Based Lateral Flow Test Strip for Rapid Detection of SARS-CoV-2 RBD Protein and N Protein

Cell Reports Physical Science ◽

10.1016/j.xcrp.2022.100740 ◽

2022 ◽

pp. 100740

Author(s):

Guo-Qiang Zhang ◽

Zhiyuan Gao ◽

Jingtian Zhang ◽

Hanlin Ou ◽

Heqi Gao ◽

...

Keyword(s):

Rapid Detection ◽

Test Strip ◽

Lateral Flow ◽

N Protein ◽

Flow Test ◽

Lateral Flow Test

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Novel Latex Microsphere Immunochromatographic Assay for Rapid Detection of Cadmium Ion in Asparagus

Foods ◽

10.3390/foods11010078 ◽

2021 ◽

Vol 11 (1) ◽

pp. 78

Author(s):

Naifeng Xu ◽

Qiaojuan Zhu ◽

Jiangxiong Zhu ◽

Jingze Jia ◽

Xinlin Wei ◽

...

Keyword(s):

Rapid Detection ◽

Limit Of Detection ◽

High Specificity ◽

Test Strip ◽

Immunochromatographic Assay ◽

Affinity Constant ◽

Quantitative Detection ◽

Cadmium Ion ◽

Copper Transporter ◽

Knock Out

Recently, concerns about heavy metal cadmium ion (Cd2+) residue in asparagus have been frequently reported, and there is an urgent need to develop an effective, sensitive, and rapid detection method for Cd2+. In this study, we innovatively combined molecular microbiology to carry out the comparative screening of Cd2+ chelators in a green, efficient, and specific way. The knock-out putative copper-transporter gene (pca1Δ) yeast strain with high sensitivity to Cd2+ was first used to screen the Cd2+ chelator, and the optimum chelator 1-(4-Isothiocyanatobenzyl)ethylenediamine-N,N,N,N′-tetraacetic acid (ITCBE) was obtained. Additionally, a rapid latex microsphere immunochromatographic assay (LMIA) was developed, based on the obtained monoclonal antibody (mAb) with high specificity and high affinity (affinity constant Ka = 1.83 × 1010 L/mol), to detect Cd2+ in asparagus. The 50% inhibitive concentration (IC50) of test strip was measured to be 0.2 ng/mL, and the limit of detection (IC10) for qualitative (LOD, for visual observation) and quantitative detection (LOQ, for data simulation) of the test strip was 2 ng/mL and 0.054 ng/mL, respectively. In all, the developed mAb-based LMIA shows a great potential for monitoring Cd2+ in asparagus, even in vegetable samples.

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Rapid detection of avian leukosis virus using a fluorescent microsphere immunochromatographic test strip assay

Poultry Science ◽

10.3382/ps/pez547 ◽

2019 ◽

Vol 98 (12) ◽

pp. 6492-6496 ◽

Cited By ~ 3

Author(s):

Huanan Wang ◽

Jianchi Guan ◽

Xiangnan Liu ◽

Yue Shi ◽

Qiwen Wu ◽

...

Keyword(s):

Rapid Detection ◽

Test Strip ◽

Avian Leukosis Virus ◽

Immunochromatographic Test ◽

Fluorescent Microsphere

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An Aggregation-Induced Emission Material Labeling Antigen-Based Lateral Flow Immunoassay Strip for Rapid Detection of Escherichia coli O157:H7

SLAS TECHNOLOGY Translating Life Sciences Innovation ◽

10.1177/2472630320981935 ◽

2021 ◽

pp. 247263032098193

Author(s):

Cheng Liu ◽

Shuiqin Fang ◽

Yachen Tian ◽

Youxue Wu ◽

Meijiao Wu ◽

...

Keyword(s):

Escherichia Coli ◽

Rapid Detection ◽

Foodborne Pathogen ◽

Test Strip ◽

Lateral Flow ◽

Detection Sensitivity ◽

Lateral Flow Immunoassay ◽

Escherichia Coli O157 ◽

Aggregation Induced Emission ◽

E Coli

Escherichia coli O157:H7 ( E. coli O157:H7) is a dangerous foodborne pathogen, mainly found in beef, milk, fruits, and their products, causing harm to human health or even death. Therefore, the detection of E. coli O157:H7 in food is particularly important. In this paper, we report a lateral flow immunoassay strip (LFIS) based on aggregation-induced emission (AIE) material labeling antigen as a fluorescent probe for the rapid detection of E. coli O157:H7. The detection sensitivity of the strip is 105 CFU/mL, which is 10 times higher than that of the colloidal gold test strip. This method has good specificity and stability and can be used to detect about 250 CFU of E. coli O157:H7 successfully in 25 g or 25 mL of beef, jelly, and milk. AIE-LFIS might be valuable in monitoring food pathogens for rapid detection.

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Direct diagnostic testing of SARS-CoV-2 without the need for prior RNA extraction

Scientific Reports ◽

10.1038/s41598-021-81487-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Shan Wei ◽

Esther Kohl ◽

Alexandre Djandji ◽

Stephanie Morgan ◽

Susan Whittier ◽

...

Keyword(s):

Limit Of Detection ◽

Point Of Care ◽

Diagnostic Testing ◽

Rna Extraction ◽

Cost Effective ◽

Clinical Samples ◽

Nasopharyngeal Swab ◽

Percentage Agreement ◽

Testing Method ◽

Viral Transport

AbstractThe COVID-19 pandemic has resulted in an urgent need for a rapid, point of care diagnostic testing that could be rapidly scaled on a worldwide level. We developed and tested a highly sensitive and robust assay based on reverse transcription loop mediated isothermal amplification (RT-LAMP) that uses readily available reagents and a simple heat block using contrived spike-in and actual clinical samples. RT-LAMP testing on RNA-spiked samples showed a limit of detection (LoD) of 2.5 copies/μl of viral transport media. RT-LAMP testing directly on clinical nasopharyngeal swab samples in viral transport media had an 85% positive percentage agreement (PPA) (17/20), and 100% negative percentage agreement (NPV) and delivered results in 30 min. Our optimized RT-LAMP based testing method is a scalable system that is sufficiently sensitive and robust to test for SARS-CoV-2 directly on clinical nasopharyngeal swab samples in viral transport media in 30 min at the point of care without the need for specialized or proprietary equipment or reagents. This cost-effective and efficient one-step testing method can be readily available for COVID-19 testing world-wide, especially in resource poor settings.

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Rapid Detection of Chloramphenicol Residues in Fermented Foods Based on UPLC-DAD

Tobacco Regulatory Science ◽

10.18001/trs.7.6.105 ◽

2021 ◽

Vol 7 (6) ◽

pp. 6303-6316

Author(s):

Weixi Gao ◽

Yan Zhuang

Keyword(s):

Rapid Detection ◽

Detection Method ◽

Original Method ◽

Fermented Food ◽

Fermented Foods ◽

Test Paper ◽

Set Up ◽

Test Process ◽

Detection Reagent ◽

Detection Speed

in the detection of chloramphenicol residues in fermented food, there are often problems of slow detection speed. Using UPLC-DAD method, a rapid detection method of chloramphenicol residues in fermented food based on UPLC-DAD method is designed. According to the characteristics of chloramphenicol, set up the detection reagent, select the detection equipment, and form the detection laboratory. It is usingUPLC-DAD method to design the test paper, using the set test reagent to deal with the sample to be tested, according to the design results of the test process, combining the reagent with the sample, to determine its specificity. Chloramphenicol residue was detected by test paper. So far, the rapid detection method of chloramphenicol residues in fermented food based on UPLC-DAD method has been designed. Compared with the original detection method, the detection speed of the detection method designed in this paper is significantly higher than the original method. In conclusion, the rapid detection method of chloramphenicol residues in fermented food based on UPLC-DAD method is effective.

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Rapid immunoassays for detection of anabolic nortestosterone in dietary supplements

Czech Journal of Food Sciences ◽

10.17221/507/2012-cjfs ◽

2013 ◽

Vol 31 (No. 5) ◽

pp. 514-519 ◽

Cited By ~ 2

Author(s):

B. Holubová ◽

S. Göselová ◽

L. Ševčíková ◽

M. Vlach ◽

M. Blažková ◽

...

Keyword(s):

Dietary Supplements ◽

Rapid Detection ◽

Visual Detection ◽

Limit Of Detection ◽

Polyclonal Antibodies ◽

Cross Reactivity ◽

Rapid Analysis ◽

Experimental Conditions ◽

Immunochromatographic Strip ◽

Strip Test

An enzyme immunoassay (ELISA) and an immunochromatographic strip were designed for a rapid detection of nortestosterone in dietary supplements. Two polyclonal antibodies and two types of nortestosterone-protein coating conjugates were tested to develop the most appropriate method. Under optimal experimental conditions, the most sensitive ELISA achieved the IC<sub>50 </sub>and the limit of detection values of 6.41 and 0.09 ng/ml, respectively. The assay specificity was tested measuring cross-reactivity of several steroids. The interference with the assay was negligible (< 0.1%), except for cross-reactivity with another frequently abused steroid testosterone (23%). The optimised gold particle-based immunochromatographic strip provided in semi-quantitative test a visual detection limit of 1 ng/ml. None of these methods showed the interference using a filtrate of the suspension of non-contaminated sample. After the validation for particular matrices, the ELISA and the strip test could be useful tools for a rapid analysis of nortestosterone in crude extracts of dietary supplements.

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