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 Recombinant Truncated Nucleocapsid Protein as Antigen in a Novel Immunoglobulin M Capture Enzyme-Linked Immunosorbent Assay for Diagnosis of Severe Acute Respiratory Syndrome Coronavirus Infection

2007 ◽  
Vol 14 (2) ◽  
pp. 146-149 ◽  
Author(s):  
Fuxun Yu ◽  
Mai Quynh Le ◽  
Shingo Inoue ◽  
Futoshi Hasebe ◽  
Maria del Carmen Parquet ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Immunosorbent Assay ◽  
Nucleocapsid Protein ◽  
Seroconversion Rate ◽  
Disease Onset ◽  
Immunoglobulin M ◽  
Antibody Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igm Antibody ◽  
Specificity And Sensitivity

ABSTRACT We report the development of an immunoglobulin M (IgM) antibody capture enzyme-linked immunosorbent assay (MAC-ELISA) for severe acute respiratory syndrome coronavirus (SARS-CoV) by using recombinant truncated SARS-CoV nucleocapsid protein as the antigen. The newly developed MAC-ELISA had a specificity and sensitivity of 100% as evaluated by using sera from healthy volunteers and patients with laboratory-confirmed SARS. Using serial serum samples collected from SARS patients, the times to seroconversion were determined by IgM antibody detection after SARS-CoV infection. The median time to seroconversion detection was 8 days (range, 5 to 17 days) after disease onset, and the seroconversion rates after the onset of illness were 33% by the first week, 97% by the second week, and 100% by the third week. Compared with the results of our previous report on the detection of IgG, the median seroconversion time by IgM detection was 3 days earlier and the seroconversion rate by the second week after the illness for IgM was significantly higher than by IgG assay. Our results indicating that the IgM response appears earlier than IgG after SARS-CoV infection in consistent with those for other pathogens. Our newly developed MAC-ELISA system offers a new alternative for the confirmation of SARS-CoV infection.

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 Longitudinal Profile of Immunoglobulin G (IgG), IgM, and IgA Antibodies against the Severe Acute Respiratory Syndrome (SARS) Coronavirus Nucleocapsid Protein in Patients with Pneumonia Due to the SARS Coronavirus

2004 ◽  
Vol 11 (4) ◽  
pp. 665-668 ◽  
Author(s):  
Patrick C. Y. Woo ◽  
Susanna K. P. Lau ◽  
Beatrice H. L. Wong ◽  
Kwok-hung Chan ◽  
Chung-ming Chu ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Indirect Immunofluorescence ◽  
Immunoglobulin G ◽  
Nucleocapsid Protein ◽  
Baseline Level ◽  
Immunofluorescence Assay ◽  
Indirect Immunofluorescence Assay ◽  
Enzyme Linked Immunosorbent Assay ◽  
Sars Coronavirus ◽  
Iga Antibodies

ABSTRACT By using a recombinant severe acute respiratory syndrome coronavirus (SARS-CoV) nucleocapsid protein-based enzyme-linked immunosorbent assay (ELISA) and serum specimens serially collected (from day 0 to day 240 after symptom onset) from patients with pneumonia due to SARS-CoV, we analyzed the longitudinal profiles of immunoglobulin G (IgG), IgM, and IgA antibodies against the SARS-CoV nucleocapsid protein in patients with pneumonia due to SARS-CoV. For IgG, the median optical density at 450 nm (OD450) turned positive at day 17 and a biphasic response was observed. At day 240, all patients were still positive for anti-nucleocapsid protein IgG antibody. For IgM, the median OD450 turned positive at day 20.5, peaked at about day 80, and fell to below the baseline level at about day 180. At day 240, 36% of the patients were still positive for anti-nucleocapsid protein IgM antibody. For IgA, the median OD450 turned positive at day 17, peaked at about day 50, and fell to below the baseline level at about day 180. At day 240, 36% of the patients were still positive for anti-nucleocapsid protein IgA antibody. The time of seroconversion detected by the recombinant SARS-CoV nucleocapsid protein-based ELISA and that detected by indirect immunofluorescence assay were similar. The median times of seroconversion for IgG, IgM, and IgA detected by the indirect immunofluorescence assay were 17 days (17 days by ELISA), 16.5 days (20.5 days by ELISA), and 17.5 days (17 days by ELISA), respectively, after disease onset. One, four, and one of the six patients who died did not produce any IgG, IgM, and IgA antibodies against the nucleocapsid protein of SARS-CoV, respectively, although these antibodies were detected in all six patients by the indirect immunofluorescence assay. Further studies should be performed to see whether SARS-CoV nucleocapsid protein antibody positivity has any prognostic significance.

scholarly journals Profile of Antibodies to the Nucleocapsid Protein of the Severe Acute Respiratory Syndrome (SARS)-Associated Coronavirus in Probable SARS Patients

2004 ◽  
Vol 11 (1) ◽  
pp. 227-228 ◽  
Author(s):  
Xuan Liu ◽  
Yulin Shi ◽  
Ping Li ◽  
Linhai Li ◽  
Yanping Yi ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Immunosorbent Assay ◽  
Nucleocapsid Protein ◽  
Healthy People ◽  
Enzyme Linked Immunosorbent Assay ◽  
High Antibody ◽  
Antibody Titers

ABSTRACT Profiles of antibodies to the nucleocapsid protein of the severe acute respiratory syndrome (SARS)-associated coronavirus in 445 probable SARS patients and 3,749 healthy people or non-SARS patients were analyzed by antigen-capturing enzyme-linked immunosorbent assay. Antinucleocapsid antibodies were elucidated in 17.5% of the probable SARS patients 1 to 7 days after the onset of symptoms and in 80% of the patients 8 to 14 days after the onset. About 90% of the probable SARS patients were positive 15 or more days after illness. Antibody titers increased up to 70 days, and high antibody titers were maintained at least for another 3 months. Of the healthy people and non-SARS patients, only seven (0.187%) were weakly positive.

scholarly journals Naturally Occurring Anti-Escherichia coli Protein Antibodies in the Sera of Healthy Humans Cause Analytical Interference in a Recombinant Nucleocapsid Protein-Based Enzyme-Linked Immunosorbent Assay for Serodiagnosis of Severe Acute Respiratory Syndrome

2006 ◽  
Vol 14 (1) ◽  
pp. 99-101 ◽  
Author(s):  
Chi Wai Yip ◽  
Chung Chau Hon ◽  
Fanya Zeng ◽  
Ken Y. C. Chow ◽  
Kwok Hung Chan ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Severe Acute Respiratory Syndrome ◽  
Immunosorbent Assay ◽  
Nucleocapsid Protein ◽  
False Positives ◽  
Enzyme Linked Immunosorbent Assay ◽  
Healthy Humans ◽  
Analytical Interference ◽  
Human Sera ◽  
Recombinant Nucleocapsid Protein

ABSTRACT We reported the analytical interference of anti-Escherichia coli protein (EP) antibodies in human sera and residual EP in a recombinant nucleocapsid protein-based enzyme-linked immunosorbent assay as a possible source of false positives in severe acute respiratory syndrome serodiagnosis. The rate of false positives was significantly reduced by adding mouse anti-EP antiserum in the blocking step.

scholarly journals Development of an Enzyme-Linked Immunosorbent Assay-Based Test with a Cocktail of Nucleocapsid and Spike Proteins for Detection of Severe Acute Respiratory Syndrome-Associated Coronavirus-Specific Antibody

2008 ◽  
Vol 16 (2) ◽  
pp. 241-245 ◽  
Author(s):  
Luis G. Giménez ◽  
Jose Rojas ◽  
Almudena Rojas ◽  
Joaquín Mendoza ◽  
Ana G. Camacho
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Immunosorbent Assay ◽  
Immunofluorescence Assay ◽  
Antibody Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Recombinant Polypeptide ◽  
Igm Antibody ◽  
Set Up ◽  
The Individual ◽  
Recombinant Polypeptides

ABSTRACT A new enzyme-linked immunosorbent assay (ELISA)-based immunoglobulin G (IgG)-plus-IgM antibody detection test for severe acute respiratory syndrome (SARS) has been developed by using a cocktail of four recombinant polypeptides as the antigen. These recombinant fragments were designed as parts of two different structural proteins from SARS-associated coronavirus (SARS-CoV). One recombinant polypeptide, S251-683, was designed as part of the spike glycoprotein, and the other three polypeptides comprised almost the whole nucleocapsid protein, avoiding the last 25 C-terminal amino acids. Immunization with a cocktail of these four polypeptides yielded a specific polyclonal antibody that is able to recognize SARS-CoV-infected cells by an immunofluorescence assay. This polypeptide cocktail was also used to set up an ELISA-based IgG-plus-IgM antibody detection test, which showed 99% specificity and 90% sensitivity upon evaluation using sera from 100 healthy negative controls and 20 SARS patients. Separate immunoreactivity assays with each recombinant polypeptide demonstrated that a combination of N and S protein fragments was more suitable than the individual peptides for developing a serological assay for SARS-CoV.

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