scholarly journals Competitive ELISA for a serologic test to detect dengue serotype-specific anti-NS1 IgGs using high-affinity UB-DNA aptamers

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ken-ichiro Matsunaga ◽  
Michiko Kimoto ◽  
Vanessa Weixun Lim ◽  
Tun-Linn Thein ◽  
Shawn Vasoo ◽  
...  

AbstractSerologic tests to detect specific IgGs to antigens related to viral infections are urgently needed for diagnostics and therapeutics. We present a diagnostic method for serotype-specific IgG identification of dengue infection by a competitive enzyme-linked immunosorbent assay (ELISA), using high-affinity unnatural-base-containing DNA (UB-DNA) aptamers that recognize the four categorized serotypes. Using UB-DNA aptamers specific to each serotype of dengue NS1 proteins (DEN-NS1), we developed our aptamer–antibody sandwich ELISA for dengue diagnostics. Furthermore, IgGs highly specific to DEN-NS1 inhibited the serotype-specific NS1 detection, inspiring us to develop the competitive ELISA format for dengue serotype-specific IgG detection. Blood samples from Singaporean patients with primary or secondary dengue infections confirmed the highly specific IgG detection of this format, and the IgG production initially reflected the serotype of the past infection, rather than the recent infection. Using this dengue competitive ELISA format, cross-reactivity tests of 21 plasma samples from Singaporean Zika virus-infected patients revealed two distinct patterns: 8 lacked cross-reactivity, and 13 were positive with unique dengue serotype specificities, indicating previous dengue infection. This antigen-detection ELISA and antibody-detection competitive ELISA combination using the UB-DNA aptamers identifies both past and current viral infections and will facilitate specific medical care and vaccine development for infectious diseases.

2021 ◽  
Author(s):  
Ken-ichiro Matsunaga ◽  
Michiko Kimoto ◽  
Vanessa Weixun Lim ◽  
Shawn Vasoo ◽  
Yee Sin Leo ◽  
...  

Abstract Serologic tests to detect IgGs specific to antigens related to viral infections are urgently needed for diagnostics and therapeutics in endemic, epidemic, and pandemic situations. We present a diagnostic method for serotype-specific IgG identification of dengue infection by a competitive enzyme-linked immunosorbent assay (ELISA), using high-affinity unnatural-base-containing DNA (UB-DNA) aptamers. Dengue is a widespread mosquito-borne viral disease, with four categorized serotypes. Using UB-DNA aptamers that bind specifically to each serotype or sub-serotype dengue NS1 protein (DEN-NS1), we developed an ELISA format with an aptamer − antibody sandwich system for dengue diagnostics. We found that IgGs highly specific to DEN-NS1 inhibit the serotype-specific NS1 detection by the ELISA format, inspiring us to develop another competitive ELISA format for serotype-specific IgG detection of dengue infection. Analyses of clinical blood samples from Singaporean patients with primary or secondary infections confirmed the highly specific IgG detection of this format, and the IgG production initially reflected the serotype of the past infection, rather than that of the recent infection. The combination of the ELISA and competitive ELISA using the UB-DNA aptamers allows the diagnosis of both past and current viral infections and will facilitate prompt and specific medical care and vaccine development for infectious diseases.


2012 ◽  
Vol 19 (5) ◽  
pp. 804-810 ◽  
Author(s):  
Stuart D. Blacksell ◽  
Richard G. Jarman ◽  
Robert V. Gibbons ◽  
Ampai Tanganuchitcharnchai ◽  
Mammen P. Mammen ◽  
...  

ABSTRACTSeven commercial assays were evaluated to determine their suitability for the diagnosis of acute dengue infection: (i) the Panbio dengue virus Pan-E NS1 early enzyme-linked immunosorbent assay (ELISA), second generation (Alere, Australia); (ii) the Panbio dengue virus IgM capture ELISA (Alere, Australia); (iii) the Panbio dengue virus IgG capture ELISA (Alere, Australia); (iv) the Standard Diagnostics dengue virus NS1 antigen ELISA (Standard Diagnostics, South Korea); (v) the Standard Diagnostics dengue virus IgM ELISA (Standard Diagnostics, South Korea); (vi) the Standard Diagnostics dengue virus IgG ELISA (Standard Diagnostics, South Korea); and (vii) the Platelia NS1 antigen ELISA (Bio-Rad, France). Samples from 239 Thai patients confirmed to be dengue virus positive and 98 Sri Lankan patients negative for dengue virus infection were tested. The sensitivities and specificities of the NS1 antigen ELISAs ranged from 45 to 57% and 93 to 100% and those of the IgM antibody ELISAs ranged from 85 to 89% and 88 to 100%, respectively. Combining the NS1 antigen and IgM antibody results from the Standard Diagnostics ELISAs gave the best compromise between sensitivity and specificity (87 and 96%, respectively), as well as providing the best sensitivity for patients presenting at different times after fever onset. The Panbio IgG capture ELISA correctly classified 67% of secondary dengue infection cases. This study provides strong evidence of the value of combining dengue virus antigen- and antibody-based test results in the ELISA format for the diagnosis of acute dengue infection.


2009 ◽  
Vol 92 (6) ◽  
pp. 1815-1820
Author(s):  
Hamdy R Soltan ◽  
Fawkia A Abd El-Megeed ◽  
Fathia I Mustafa ◽  
Hanafy M Ismail

Abstract A sensitive and selective indirect competitive ELISA was developed for the detection of deltamethrin bound residues on cotton texture. Cross-reactivity studies with the main deltamethrin photodegradation products showed high specificity of deltamethrin polyclonal antibody to the parent compound. No cross-reactivity was measured with deltamethrin photodegradtion products derived from the alcohol moiety (3-phenoxybenzaldhyde, phenoxybenzyl alcohol, cyanohydrin, and 3-phenoxybenzoic acid), and lesser amounts were observed with the acid moiety (deltamethric acid). The dot-blot immunoassay was performed on cotton fabric discs spiked with deltamethrin and irradiated to assess the suitability of this system to detect bound residue. The dot-blot immunoassay results revealed that the bound form of deltamethrin has binding affinity with deltamethrin antibody similar to the parent compound. In addition, the test system was used to detect bound and free residues of deltamethrin on cotton samples exposed to three cycles of simulated sunlight and water wash. The results obtained suggest that the competitive ELISA format can be used as a tool for monitoring free and bound residues of deltamethrin impregnated on cotton targets.


1994 ◽  
Vol 57 (2) ◽  
pp. 146-149 ◽  
Author(s):  
P. MORALES ◽  
T. GARCÍA ◽  
I. GONZÁLEZ ◽  
R. MARTÍN ◽  
B. SANZ ◽  
...  

A stable hybridoma cell line (DD9) has been produced secreting a monoclonal antibody specific for porcine muscle proteins. The DD9 monoclonal antibody (mAb) failed to show a significant cross-reactivity when tested against beef, horse, chicken, and soya proteins, as well as bovine caseins, gelatin, and bovine serum albumin. The DD9 mAb was further used in an indirect ELISA format for detection of defined amounts of porcine meat (1–100%) in beef and chicken meat mixtures immobilized on 96-well plates. Immunorecognition of monoclonal antibodies adsorbed to porcine meat was made with rabbit anti-mouse immunoglobulins conjugated to the enzyme horseradish peroxidase.


1993 ◽  
Vol 13 (2) ◽  
pp. 99-105 ◽  
Author(s):  
Jan Holm ◽  
Steen Ingemann Hansen ◽  
Mimi Høier-Madsen

Binding of 3H-folate in Triton X-100 solubilized human prostate homogenate was of a high-affinity type and displayed apparent positive cooperativity typical of specific folate binding. Radioligand dissociation was slow at pH 7.4, but rapid at pH 3.5. Gel chromatography reveled two major folate binding proteins (Mr≈100 and 25kDa), but only one single band (Mr ≈ 65–70 kDa) was detectable on SDS-PAGE and immunoblotting with rabbit-anti human milk folate binding protein. Concentration of folate binding protein in prostate homogenate expressed as maximum 3H-folate binding was 1.10 nmol/g protein, and the cross-reactivity with rabbit-anti human milk folate binding protein serum was 15% as determined by an enzyme-linked immunosorbent assay (median values; n = 6).


Biosensors ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 7
Author(s):  
Shira Avivi-Mintz ◽  
Yaniv Lustig ◽  
Victoria Indenbaum ◽  
Eli Schwartz ◽  
Amos Danielli

Sensitive serological assays are needed to provide valuable information about acute and past viral infections. For example, detection of anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgG antibodies could serve as the basis for an “immunity passport” that would enable individuals to travel internationally. Here, utilizing a novel Magnetic Modulation Biosensing (MMB) system and the receptor-binding domain of the SARS-CoV-2 spike protein, we demonstrate a highly sensitive and specific anti-SARS-CoV-2 IgG serological assay. Using anti-SARS-CoV-2 IgG antibodies, RT-qPCR SARS-CoV-2-positive and healthy patients’ samples, and vaccinees’ samples, we compare the MMB-based SARS-CoV-2 IgG assay’s analytical and clinical sensitivities to those of the enzyme-linked immunosorbent assay (ELISA). Compared with ELISA, the MMB-based assay has an ~6-fold lower limit of detection (129 ng/L vs. 817 ng/L), and it detects an increase in the IgG concentration much earlier after vaccination. Using 85 RT-qPCR SARS-CoV-2-positive samples and 79 -negative samples, the MMB-based assay demonstrated similar clinical specificity (98% vs. 99%) and sensitivity (93% vs. 92%) to the ELISA test, but with a much faster turnaround time (45 min vs. 245 min). The high analytical and clinical sensitivity, short turnaround time, and simplicity of the MMB-based assay makes it a preferred method for antibody detection.


1992 ◽  
Vol 108 (3) ◽  
pp. 457-462 ◽  
Author(s):  
M. J. Webberley ◽  
J. M. Webberley ◽  
D. G. Newell ◽  
P. Lowe ◽  
V. Melikian

SUMMARYAn enzyme-linked immunosorbent assay has been used to diagnose serologically the prevalence ofHelicobacter pyloriinfection in Asian life-long vegans. There was no difference in the seropositivity between these individuals and a group of age-and sex-matched Asian meat-eaters, indicating the meat consumption is not a risk factor forH. pyloriinfection. However, both Asian groups had a higher prevalence of infection than age- and sex-matched Caucasian meat-eaters. Additionally, the Asian individuals had a wider range of specific IgG antibody concentrations than the Caucasians. This did not appear to be due to antigenic cross-reactivity betweenH. pyloriandCampylobacter jejuni. The significance of these observations to the establishment of cut-off levels for the serodiagnosis of certain ethnic groups is discussed.


2017 ◽  
Vol 55 (6) ◽  
pp. 1894-1901 ◽  
Author(s):  
Yaniv Lustig ◽  
Hana Zelena ◽  
Giulietta Venturi ◽  
Marjan Van Esbroeck ◽  
Camilla Rothe ◽  
...  

ABSTRACT Serological diagnosis of Zika virus is challenging due to high cross-reactivity of Zika virus with other flavivirus antibodies. Recently, a Zika NS1-based enzyme-linked immunosorbent assay (ELISA) was developed and shown to be highly specific for Zika antibody detection; however, sensitivity was evaluated for only a small number of confirmed Zika-infected patients. In this study, we measured the sensitivity and kinetics of Zika IgM and IgG antibodies using the Zika NS1-based ELISA in 105 samples from 63 returning travelers infected with Zika virus (proven by PCR or neutralization assay) from Israel, Czech Republic, Italy, Belgium, Germany, and Chile. Zika virus IgM was detected from 2 to 42 days post-symptom onset (PSO) with an overall sensitivity of 79% in the first month and 68% until 2 months PSO, while IgG antibodies were detected from 5 days to 3 years PSO with 79% sensitivity. Interestingly, significant differences in IgM sensitivity and IgM detection period were observed between Israeli and European/Chilean Zika-infected travelers, adding to the complexity of Zika infection diagnosis and suggesting that other diagnostic methods should be complemented to reduce false-negative results.


Author(s):  
Vijayalakshmi Nandakumar ◽  
Tracie Profaizer ◽  
Bucky K. Lozier ◽  
Marc G. Elgort ◽  
Erin T. Larragoite ◽  
...  

ABSTRACT Context: Emerging evidence shows correlation between the presence of neutralization antibodies (nAbs) and protective immunity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Currently available commercial serology assays lack the ability to specifically identify nAbs. An ELISAbased nAb assay (GenScript cPass neutralization antibody assay) has recently received emergency use authorization from the Food and Drug Administration (FDA). Objective: To evaluate the performance characteristics of this assay and compare and correlate it with the commercial assays that detect SARS-CoV-2 specific IgG. Design: Specimens from SARS-COV-2 infected patients (n=124), healthy donors obtained pre-pandemic (n=100), and from patients with non-COVID (coronavirus disease 2019) respiratory infections (n=92) were analyzed using this assay. Samples with residual volume were also tested on three commercial serology platforms (Abbott, EUROIMMUN, Siemens). Twenty-eight randomly selected specimens from patients with COVID-19 and 10 healthy controls were subjected to a Plaque Reduction Neutralization Test (PRNT). Results: The cPass assay exhibited 96.1% (95% CI, 94.9%–97.3%) sensitivity (at >14 days post- positive PCR), 100% (95% CI, 98.0%–100.0%) specificity and zero cross-reactivity for the presence of non- COVID respiratory infections. When compared to the plaque reduction assay, 97.4% (95% CI, 96.2%–98.5%) qualitative agreement and a positive correlation (R2 =0.76) was observed. Comparison of IgG signals from each of the commercial assays with the nAb results from PRNT/cPass assays displayed >94.7% qualitative agreement and correlations with R2=0.43/0.68 (Abbott), R2=0.57/0.85 (EUROIMMUN) and R2=0.39/0.63 (Siemens), respectively. Conclusions: The combined data support the use of cPass assay for accurate detection of the nAb response. Positive IgG results from commercial assays associated reasonably with nAbs presence and can serve as a substitute.


1988 ◽  
Vol 255 (6) ◽  
pp. F1197-F1205 ◽  
Author(s):  
E. M. Worcester ◽  
Y. Nakagawa ◽  
C. L. Wabner ◽  
S. Kumar ◽  
F. L. Coe

Urine inhibition of calcium oxalate monohydrate (COM) crystal growth (CG) seems due to a glycoprotein that contains gamma-carboxyglutamic acid and has been named nephrocalcin (NC); however, Tamm-Horsfall protein (THP) and albumin resemble NC and make its measurement and role uncertain. NC in urine is aggregated to molecular mass 64 kDa and higher, similar to albumin (64 kDa) and THP (87 kDa). Albumin and THP are calcium binding, albumin adsorbs to COM crystals, and THP has been described as an inhibitor of COM growth. Antisera to NC have cross-reacted with THP even though the NC was isolated from cultured renal cells. Here we have compared highly purified NC, THP, and albumin adsorption with COM crystals and CG inhibition; also we compared their patterns of cross-reactivities with a new antiserum against NC and a monoclonal antibody to THP. NC adsorbs to COM crystals, THP does not. Albumin and THP do not inhibit CG. Cross-reactivity of albumin and THP to the antiserum is slight by direct enzyme-linked immunosorbent assay and nonexistent by competitive ELISA; reaction of NC to the anti-THP monoclonal antibody is absent.


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