scholarly journals N protein‐based ultrasensitive SARS‐CoV‐2 antibody detection in seconds via 3D nanoprinted, microarchitected array electrodes

2022 ◽  
Author(s):  
Md. Azahar Ali ◽  
Chunshan Hu ◽  
Fei Zhang ◽  
Sanjida Jahan ◽  
Bin Yuan ◽  
...  
Keyword(s):  
Antibody Detection ◽  
N Protein

scholarly journals Specificity of SARS-CoV-2 antibody-detection assays against S and N protein among pre-COVID-19 sera from patients with protozoan and helminth parasitic infections

2021 ◽  
Author(s):  
Cedric P Yansouni ◽  
Jesse Papenburg ◽  
Matthew P Cheng ◽  
Rachel Corsini ◽  
Chelsea Caya ◽  
...  
Keyword(s):  
Rapid Test ◽  
Reticuloendothelial System ◽  
Antibody Detection ◽  
Parasitic Infections ◽  
N Protein ◽  
Lower Specificity ◽  
Protozoan Infections ◽  
Test Specificity ◽  
Positive Results ◽  
Abbott Architect

Background: We aimed to assess the specificity of SARS-CoV-2 antibody detection assays among people with known tissue-borne parasitic infections. Methods: We tested three SARS-CoV-2 antibody-detection assays (cPass SARS-CoV-2 Neutralization Antibody Detection Kit, Abbott SARS-CoV-2 IgG assay, and STANDARD Q COVID-19 IgM/IgG Combo Rapid Test) among 559 pre-COVID-19 sera. Results: The specificity of assays was 95-98% overall. However, lower specificity was observed among sera from patients with protozoan infections of the reticuloendothelial system, such as human African trypanosomiasis (Abbott Architect; 88% [95%CI 75-95]), visceral leishmaniasis (SD RDT IgG; 80% [95%CI 30-99]), and from patients with recent malaria from a holoendemic area of Senegal (ranging from 91% for Abbott Architect and SD RDT IgM to 98-99% for cPass and SD RDT IgG). For specimens from patients with evidence of past or present helminth infection overall, test specificity estimates were all ≥ 96%. Sera collected from patients clinically suspected of parasitic infections that tested negative for these infections yielded a specificity of 98-100%. The majority (>85%) of false-positive results were positive by only one assay. Conclusions: The specificity of SARS-CoV-2 serological assays among sera from patients with tissue-borne parasitic infections was below the threshold required for decisions about individual patient care. Specificity is markedly increased by the use of confirmatory testing with a second assay. Finally, the SD RDT IgG proved similarly specific to laboratory-based assays and provides an option in low-resource settings when detection of anti-SARS-CoV-2 IgG is indicated.

scholarly journals Diagnostic Performance of Three Serological Assays for Anti-SARS-CoV-2 Antibody Detection

2021 ◽  
Vol 5 (4) ◽  
pp. 162-165
Author(s):  
Shabnam Dildar ◽  
◽  
Asma Danish ◽  
Mehjabeen Imam ◽  
Arshi Naz ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Diagnostic Performance ◽  
Immunofluorescence Assay ◽  
Lateral Flow ◽  
Antibody Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Perfect Agreement ◽  
N Protein ◽  
Assay Performance ◽  
Antibody Elisa

Abstract: Objective: To evaluate the diagnostic performance of Electrochemiluminescence (ECLIA) enzyme linked immunosorbent (ELISA) and lateral flow Immunofluorescence (LFIA) for anti-SARS-COV-2 antibody detection. Materials and Methods: Sensitivity was calculated with convalescent plasma (CP) donor’s samples. Specificity was checked by using pre-pandemic October 2019 samples. All samples were tested for anti-SARS-COV-2 antibody by using Electrochemiluminescence (ECLIA), Enzyme Linked Immunosorbent Assay (ELISA) and Lateral flow Immunofluorescence (LFIA) assay. Results: Total 55 patients were included, 45 patients were CP donors and 10 were Pre-Pandemic October 2019 samples archived from our blood bank. The ECLIA-total antibody, ELISA-IgG and LLFIA-IgG were positive in 41 (91.1%), 34 (75.5%) and 44 (97.75%) respectively. The highest sensitivity was observed for LFIA with highest specificity among all three assays. There was almost perfect agreement between LFIA and ECLIA (k=0.936, p<0.001) but there was fair agreement between LFIA and ELISA (k=0.412, p=0.001) and ECLIA and ELISA (k=0.357, p=0.001). Conclusion: The LFIA showed a higher sensitivity and specificity in comparison with ECLIA and ELISA. It might be due to fact that LFIA detect antibody against ncleocapsid and spike protein as well of SARS- COV-2 virus, while ECLIA and ELISA detects antibodies only against “N” Protein of SARS- COV-2 virus. Keywords: Convalescent plasma donors, Lateral flow Immunofluorescence assay, Electrochemiluminescence assay, Enzyme linked immunosorbent assay, Performance.

scholarly journals Sonchus Yellow Net Rhabdovirus Nuclear Viroplasms Contain Polymerase-Associated Proteins

1998 ◽  
Vol 72 (7) ◽  
pp. 5669-5679 ◽  
Author(s):  
Claudia R. F. Martins ◽  
Jennifer A. Johnson ◽  
Diane M. Lawrence ◽  
Tae-Jin Choi ◽  
Anna-Maria Pisi ◽  
...  
Keyword(s):  
Potato Virus X ◽  
Antibody Detection ◽  
N Gene ◽  
Rna Sequences ◽  
N Protein ◽  
Associated Proteins ◽  
Multiple Regions ◽  
Infected Cells ◽  
In Situ Hybridizations ◽  
Pvx Vector

ABSTRACT We have initiated a study of the cytopathology of nucleorhabdoviruses by analyzing the subcellular localization of sonchus yellow net virus (SYNV) genomic and antigenomic RNAs and the encoded polymerase proteins. In situ hybridizations demonstrated that the minus-strand genomic RNA sequences are restricted to the nuclei of infected cells, while the complementary plus-strand antigenomic RNA sequences are present in both the nuclei and the cytoplasm. Immunofluorescence and immunogold labeling experiments also revealed that the nucleocapsid (N) protein and phosphoprotein (M2) are primarily localized to discrete regions within the nuclei and in virus particles that accumulate in perinuclear spaces. The N protein antiserum specifically labeled the nuclear viroplasms, whereas the M2 antiserum was more generally distributed throughout the nuclei. Antibody detection also indicated that the polymerase (L) protein is present in small amounts in the viroplasm. When the N and M2 proteins were expressed individually from the heterologous potato virus X (PVX) vector, both proteins preferentially accumulated in the nuclei. In addition, viroplasm-like inclusions formed in the nuclei of cells infected with the PVX vector containing the N gene. Fusions of the carboxy terminus of β-glucuronidase to N and M2 resulted in staining of the nuclei of infected cells following expression from the PVX vector. Deletion analyses suggested that multiple regions of the N protein contain signals that are important for nuclear localization.

scholarly journals Quantitative, Epitope-specific, Serological Screening of COVID-19 Patients Using a Novel Multiplexed Array-based Immunoassay Platform

2020 ◽  
Author(s):  
Jonathan M Blackburn ◽  
Nur Diana Anuar ◽  
Ti-Myen Tan ◽  
Andrew JM Nel ◽  
Muneerah Smith ◽  
...  
Keyword(s):  
Natural Infection ◽  
High Titre ◽  
Antibody Detection ◽  
Virus Infections ◽  
Serum Samples ◽  
Serological Screening ◽  
N Protein ◽  
Antibody Reactivity ◽  
Positive Antibody ◽  
Single Target

Following the COVID-19 pandemic outbreak in late 2019, a large number of antibody tests were developed for use in seroprevalence studies aimed at determining the extent of current or previous SARS-CoV-2 virus infections in a given population. The vast majority of these tests are qualitative and use a single target for antibody detection, incorporating either full-length or truncated versions of the nucleocapsid (N) or spike (S) proteins from SARS-CoV-2. Importantly, mono-epitope tests - whether qualitative or quantitative - are unable to localise antibody binding or characterise the distribution and titres of epitope recognition by anti-SARS-CoV-2 antibodies within an individual or across a population. However, it seems plausible that if such information were available, it may correlate with the presence of potent, high-titre, neutralising antibodies that afford protection again imminent re-infection, as well as with the likelihood of developing a memory B-cell response that would provide more durable protection. We have developed a novel, quantitative, multi-antigen, multiplexed, array-based immunoassay platform, ImmuSAFE COVID+ (ImmuSAFE) comprising 6 functionally validated domains or regions of the N protein of SARS-CoV-2 expressed using Sengenics KREX technology. This array platform enables determination of both the position and breadth of anti-SARS-CoV-2 antibody responses following natural infection or vaccination. To validate our platform, 100 serum samples (confirmed sero-positive COVID-19 cases, n=50; pre-pandemic HIV positive controls, n=50) were tested for IgG seropositivity to the N antigen, yielding 100% specificity and 100% sensitivity. All 50 cases showed positive antibody reactivity towards at least one N protein epitope, whilst all 50 controls showed antibody reactivity below threshold values. Broad variation was also observed in the magnitude and breadth of antibodies present, represented as an Epitope Coverage score (EPC). A positive correlation was observed between increasing age and EPC values, with individuals under 40 years old having a mean EPC score of 3.1, whilst individuals above the age of 60 had a mean EPC of 5.1. This finding may have broad implications for the natural history of COVID-19 disease in different individuals.

scholarly journals Use of the COOH Portion of the Nucleocapsid Protein in an Antigen-Capturing Enzyme-Linked Immunosorbent Assay for Specific and Sensitive Detection of Severe Acute Respiratory Syndrome Coronavirus

2005 ◽  
Vol 12 (3) ◽  
pp. 474-476 ◽  
Author(s):  
Maofeng Qiu ◽  
Jin Wang ◽  
Hongxia Wang ◽  
Zeliang Chen ◽  
Erhei Dai ◽  
...  
Keyword(s):  
Amino Acids ◽  
Severe Acute Respiratory Syndrome ◽  
Epidemiological Study ◽  
Immunosorbent Assay ◽  
Nucleocapsid Protein ◽  
Antibody Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Sars Coronavirus ◽  
Specific Test ◽  
N Protein

ABSTRACT Antibody detection with a recombinant COOH portion of the severe acute respiratory syndrome (SARS) coronavirus nucleocapsid (N) protein, N13 (amino acids 221 to 422), was demonstrated to be more specific and sensitive than that with the full-length N protein, and an N13-based antigen-capturing enzyme-linked immunosorbent assay providing a convenient and specific test for serodiagnosis and epidemiological study of SARS was developed.

scholarly journals Proteome-wide analysis of differentially-expressed SARS-CoV-2 antibodies in early COVID-19 infection

2020 ◽  
Author(s):  
Xiaomei Zhang ◽  
Xian Wu ◽  
Dan Wang ◽  
Minya Lu ◽  
Xin Hou ◽  
...  
Keyword(s):  
Early Stage ◽  
False Negative ◽  
False Negative Rate ◽  
Antibody Detection ◽  
Igg Antibodies ◽  
Protein Subunit ◽  
Igg Antibody ◽  
S Protein ◽  
N Protein ◽  
Acute Myocardial Injury

AbstractRapid and accurate tests that detect IgM and IgG antibodies to SARS-CoV-2 proteins are essential in slowing the spread of COVID-19 by identifying patients who are infected with COVID-19. Using a SARS-CoV-2 proteome microarray developed in our lab, we comprehensively profiled both IgM and IgG antibodies in forty patients with early-stage COVID-19, influenza, or non-influenza who had similar symptoms. The results revealed that the SARS-CoV-2 N protein is not an ideal biomarker for COVID-19 diagnosis because of its low immunogenicity, thus tests that rely on this marker alone will have a high false negative rate. Our data further suggest that the S protein subunit 1 receptor binding domain (S1-RBD) might be the optimal antigen for IgM antibody detection, while the S protein extracellular domain (S1+S2ECD) would be the optimal antigen for both IgM and IgG antibody detection. Notably, the combination of all IgM and IgG biomarkers can identify 87% and 73.3% COVID-19 patients, respectively. Finally, the COVID-19-specific antibodies are significantly correlated with the clinical indices of viral infection and acute myocardial injury (p≤0.05). Our data may help understand the function of anti-SARS-CoV-2 antibodies and improve serology tests for rapid COVID-19 screening.

scholarly journals High-Specificity Targets in SARS-CoV-2 N Protein for Serological Antibody Detection

2020 ◽  
Author(s):  
Jianhai Yu ◽  
Zhiran Qin ◽  
Xiaoen He ◽  
Xuling Liu ◽  
Jinxiu Yao ◽  
...  
Keyword(s):  
Amino Acid Level ◽  
Cell Epitope ◽  
High Specificity ◽  
Cross Reactivity ◽  
Serological Diagnosis ◽  
Detection Methods ◽  
Antibody Detection ◽  
Nucleic Acid Detection ◽  
N Protein ◽  
Antibody Levels

Abstract Background The current coronavirus disease (COVID-19) pandemic has created a pressing need to diagnose and screen a large number of close contacts of confirmed and suspected cases. Numerous nucleic acid detection kits are being rapidly developed and approved for viral etiological diagnosis; however, these are limited by the number of false negatives produced in clinical practice. Therefore, there is an urgent need to establish serological detection methods to serve as supplementary diagnostics. Methods We (1) performed a conservation and specificity analysis of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid (N) protein, which is the main target of serological diagnosis; (2) integrated various B-cell epitope prediction methods to obtain possible dominant epitope regions for the N protein; (3) applied ELISA to analyze differences in the serological antibody levels for different epitopes; and (4) identified N protein epitopes for IgG and IgM with high specificity. Results SARS-CoV-2 strains showed low mutation rates for the N protein, and the construction of a phylogeny was a good characterization of its molecular evolutionary lineage in relation to other coronaviruses. SARS-CoV-2 showed the closest genetic relationship with SARS-CoV, which showed multiple consecutive long conserved regions at the amino acid level, but differed substantially from other coronaviruses. Tests targeting the SARS-CoV-2 N protein produced strong positive results in SARS-CoV patients in recovery. Of the five epitope dominant regions, using N18-39 and N183-197 for IgG and IgM detection, respectively, can effectively overcome the limitations of cross-reactivity. Conclusions The patients infected with both SARS viruses may exhibit cross-reactivity when using the N protein for antibody detection. However, there are regions of the N protein that can be used for antibody detection and some of these regions showed good specificity even between SARS-CoV-2 and SARS-CoV, and the antibody levels detected were consistent with those detected by the complete N protein. These findings provide a basis for serological diagnosis of SARS-CoV-2 patients, and research ideas for developing vaccines.

scholarly journals The C-Terminal Half of SARS-CoV-2 Nucleocapsid Protein, Industrially Produced in Plants, Is Valid as Antigen in COVID-19 Serological Tests

2021 ◽  
Vol 12 ◽  
Author(s):  
Laura Williams ◽  
Silvia Jurado ◽  
Francisco Llorente ◽  
Alberto Romualdo ◽  
Sara González ◽  
...  
Keyword(s):  
Diagnostic Tests ◽  
Cost Effective ◽  
City Council ◽  
Antibody Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rt Pcr ◽  
Serological Tests ◽  
K Value ◽  
N Protein ◽  
Effective Manner

BackgroundThe fight against the current coronavirus disease 2019 (COVID-19) pandemic has created a huge demand of biotechnological, pharmaceutical, research and sanitary materials at unprecedented scales. One of the most urgent demands affects the diagnostic tests. The growing need for rapid and accurate laboratory diagnostic tests requires the development of biotechnological processes aimed at producing reagents able to cope with this demand in a scalable, cost-effective manner, with rapid turnaround times. This is particularly applicable to the antigens employed in serological tests. Recombinant protein expression using plants as biofactories is particularly suitable for mass production of protein antigens useful in serological diagnosis, with a neat advantage in economic terms.MethodsWe expressed a large portion of the nucleoprotein (N) derived from SARS-CoV-2 in Nicotiana benthamiana plants. After purification, the recombinant N protein obtained was used to develop an indirect enzyme-linked immunosorbent assay (ELISA) for detection of antibodies to SARS-CoV-2 in human sera. To validate the ELISA, a panel of 416 sera from exposed personnel at essential services in Madrid City Council were tested, and the results compared to those obtained by another ELISA, already validated, used as reference. Furthermore, a subset of samples for which RT-PCR results were available were used to confirm sensitivity and specificity of the test.ResultsThe performance of the N protein expressed in plants as antigen in serologic test for SARS-CoV-2 antibody detection was shown to be highly satisfactory, with calculated diagnostic sensitivity of 96.41% (95% CI: 93.05–98.44) and diagnostic specificity of 96.37 (95% CI: 93.05–98.44) as compared to the reference ELISA, with a kappa (K) value of 0.928 (95% CI:0.892–0.964). Furthermore, the ELISA developed with plant-derived N antigen detected SARS-CoV-2 antibodies in 84 out of 93 sera from individuals showing RT-PCR positive results (86/93 for the reference ELISA).ConclusionThis study demonstrates that the N protein part derived from SARS-CoV-2 expressed in plants performs as a perfectly valid antigen for use in COVID-19 diagnosis. Furthermore, our results support the use of this plant platform for expression of recombinant proteins as reagents for COVID-19 diagnosis. This platform stands out as a convenient and advantageous production system, fit-for-purpose to cope with the current demand of this type of biologicals in a cost-effective manner, making diagnostic kits more affordable.

DETEKSI ANTIBODI MULTIPEL HEPATITIS C DALAM DARAH DONOR

2016 ◽  
Vol 21 (3) ◽  
pp. 261
Author(s):  
Ranti Permatasari ◽  
Aryati Aryati ◽  
Budi Arifah
Keyword(s):  
Hepatitis C ◽  
Predictive Value ◽  
Core Protein ◽  
Rapid Test ◽  
Antibody Test ◽  
Diagnostic Value ◽  
Hcv Infection ◽  
Antibody Detection ◽  
Hcv Rna ◽  
Hcv Antibody

Hepatitis C (HCV) infection could be spread by blood transfusion. Screening of HCV in donor blood could prevent HCV infection to the recipient. HCV antibody test using rapid test of multiple antibody detection by immunochromatography method is an easy and rapid test that could detect four HCV antibodies separately. The aim of this study was to evaluate the diagnostic value of antibody HCV using multiple antibody detection rapid test in diagnosing HCV infection. This was an analytical observational study with a cross sectional design. The samples consisted of 42 donors’ blood serum from the Surabaya Branch of the Indonesian Red Cross which underwent HCV infection test using ELISA method. The samples were then tested using PCR HCV RNA as the gold standard and antibody HCV multiple antibodydetection rapid test The diagnostic value of HCV antibody test using multiple antibody detection rapid test by immunochromatography method showed a diagnostic sensitivity of 100%, diagnostic specificity of 75%, positive predictive value of 66.7% and negative predictive value of 100%, a diagnostic efficiency of 83.3%, with a positive probability ratio of 4 times. The most often positive antibody pattern was four (4) positive antibodies (core protein, NS3, NS4 and NS5). Core protein (CP) and NS3 were the most often positive antibodies. Based on this study result, the HCV antibody test using multiple antibody detection rapid test by immunochromatography method has a good diagnostic value.

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