scholarly journals Analysis of Photochemically Induced Cotton Bound Residues of Deltamethrin by an Immunoassay Technique

2009 ◽  
Vol 92 (6) ◽  
pp. 1815-1820
Author(s):  
Hamdy R Soltan ◽  
Fawkia A Abd El-Megeed ◽  
Fathia I Mustafa ◽  
Hanafy M Ismail
Keyword(s):  
Parent Compound ◽  
High Specificity ◽  
Test System ◽  
Cross Reactivity ◽  
Competitive Elisa ◽  
Dot Blot ◽  
Bound Residues ◽  
Elisa Format ◽  
Photodegradation Products ◽  
Bound Residue

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.

scholarly journals Monoclonal antibodies to a phosphoprotein from chromatin of rat liver

1985 ◽  
Vol 225 (2) ◽  
pp. 357-363 ◽  
Author(s):  
M J Halikowski ◽  
C C Liew
Keyword(s):  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
Bovine Serum Albumin ◽  
Rat Liver ◽  
High Specificity ◽  
Cross Reactivity ◽  
Dot Blot ◽  
Chromosomal Proteins ◽  
Rat Liver Nuclei ◽  
Liver Nuclei

Three monoclonal antibody subclasses (IgG1, IgG2a, and IgM) were raised to the phosphoprotein B2 (Mr 68000, pI6.5-8.2) which has been shown previously to be associated with the nucleosomes of rat liver nuclei. These antibodies do not show any significant cross reactivity with CM-cellulose ‘unbound’ non-histone chromosomal proteins, bovine serum albumin or histones. Further verification of the specificity of these antibodies to this phosphoprotein was carried out using both ‘dot’ blot and immunological transfer analysis (‘Western blot‘). The monoclonal antibodies (IgG1 and IgG2a) could also be used to semi-quantify the phosphoprotein B2 in rat liver nuclei. The high specificity and unlimited availability of this type of probe provides a means to study the role(s) of this phosphoprotein in the overall scheme of actively transcribed chromatin.

Affiblot: A dot blot-based screening device for selection of reliable antibody

2021 ◽  
Author(s):  
Zuzana Svobodová ◽  
Jakub Novotny ◽  
Barbora Ospalkova ◽  
Marcela Slovakova ◽  
Zuzana Bilkova ◽  
...  
Keyword(s):  
High Specificity ◽  
Cross Reactivity ◽  
Dot Blot ◽  
Key Factor ◽  
Screening Device ◽  
Selection Of

The key factor in the development of antibody-based assays is to find an antibody that has an appropriate affinity, high specificity, and low cross-reactivity. However, this task is not easy...

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 ◽  
...  
Keyword(s):  
Viral Infections ◽  
Dengue Infection ◽  
Cross Reactivity ◽  
Competitive Elisa ◽  
Antibody Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Dna Aptamers ◽  
High Affinity ◽  
Elisa Format ◽  
Specific Igg

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.

scholarly journals Evaluation of the sensitivity and specificity of GST-tagged recombinant antigens 2B2t, Ag5t and DIPOL in ELISA for the diagnosis and follow up of patients with cystic echinococcosis

2020 ◽  
Vol 14 (11) ◽  
pp. e0008892
Author(s):  
Carlos Sánchez-Ovejero ◽  
Eylem Akdur ◽  
Raúl Manzano-Román ◽  
Ana Hernández-González ◽  
María González-Sánchez ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
Cystic Echinococcosis ◽  
Alveolar Echinococcosis ◽  
High Specificity ◽  
Cross Reactivity ◽  
Response To Treatment ◽  
Confirmatory Test ◽  
Positive Serology ◽  
Elisa Format

Cystic echinococcosis (CE) is a neglected zoonotic disease caused by Echinococcus granulosus sensu lato. Diagnosis and monitoring of CE rely primarily on imaging while serology is used as a confirmatory test. However, imaging is not always conclusive and currently available serological assays have suboptimal sensitivity and specificity, lack standardization, and are not useful for patients´ follow-up. Seroassays for CE are usually based on hydatid fluid (HF), a complex, variable antigenic mixture, and cross-reactivity exists especially with alveolar echinococcosis. Recombinant proteins based on immunogenic antigens most abundant in HF, such as AgB1, AgB2 and Ag5, have been used to overcome these limitations. None of them so far showed potential to replace HF; however, their performance have been largely tested on a limited number of samples, and comparison of different antigens using the same cohort has been rarely performed. The combination of several immunogenic epitopes in a single recombinant protein could enhance test sensitivity. For the diagnosis and follow-up of patients with CE, we compared the performance of the crude HF, previously described recombinant 2B2t antigen, and GST-tagged version of 2B2t, and novel designed recombinants (GST-Ag5t and the GST-DIPOL chimera containing AgB1, AgBB2 and Ag5 epitopes) by IgG-ELISA format. Samples belong to a retrospective cohort of 253 well-characterized patients with CE, previously described for the evaluation of the 2B2t antigen, 92 patients with alveolar echinococcosis, and 82 healthy donors. The reference standard for CE diagnosis was the presence of a CE lesion as diagnosed by ultrasonography. The highest sensitivity was obtained with HF [86.7%, 95% confidence interval (CI): 81.2–91.0], followed by GST-2B2t (70.0%, 95% CI: 63.1–76.2), 2B2t (65.5%, 95% CI: 58.5–72.0), GST-Ag5t (64.5%, 95% CI: 57.5–71.1) and GST-DIPOL (63.1%, 95% CI: 56.0–69.7). The GST-2B2t had the best specificity (95.8%, 95% CI: 88.3–99.1) and the lowest cross-reactivity (38.7%, 95% CI: 27.6–50.6). Good response to treatment also correlated to negative test results in the GST-2B2t ELISA. While none of the tested recombinant antigen appears suitable to replace HF for the diagnosis of CE, GST-2B2t should be further explored as a confirmation test, based on its high specificity and low cross-reactivity, and for the follow-up after treatment in those patients with positive serology for this antigen.

Development and Optimization of a mAb-Based Indirect Competitive ELISA for Enrofloxacin Residue in Duck

2011 ◽  
Vol 48-49 ◽  
pp. 423-427 ◽  
Author(s):  
Jin Qing Jiang ◽  
Hai Tang Zhang ◽  
Heng Zhang Zhao ◽  
Kun Zhao ◽  
Zhi Yong Xu ◽  
...  
Keyword(s):  
Monitoring Program ◽  
High Specificity ◽  
Cross Reactivity ◽  
Competitive Elisa ◽  
Rapid Screening ◽  
Experimental Conditions ◽  
Elisa System ◽  
Indirect Competitive Elisa ◽  
Quantitative Monitoring ◽  
Poultry Tissues

This paper presents the generation of monoclonal antibodies (mAbs) with high specificity against enrofloxacin (ENR) through cell fusion procedures, and the development of a mAb-based indirect competitive ELISA (icELISA) method to detect ENR residue using one of these Hybridomas (clone 4B5-D6). Under the optimal experimental conditions, this assay exhibited a working range of 0.004-38 ng/mL with IC50 and LOD values of 0.4 and 0.002 ng/mL, respectively. Except for a high cross-reactivity (105.2%) to Ciprofloxacin, negligible cross-reactivity to the other compounds was observed. After optimization, 10% of methanol was used in the assay buffer and this ELISA system can tolerate acetonitrile not higher than 10%. Recovery studies indicate that an excellent correlation between concentration spiked and concentration determined was found, and the results also suggest this assay has the potential to be incorporated into a quantitative monitoring program for the rapid screening of ENR residue in poultry tissues.

scholarly journals A 16S rDNA-based nested PCR protocol to detect Campylobacter gracilis in oral infections

2003 ◽  
Vol 17 (2) ◽  
pp. 142-146 ◽  
Author(s):  
José Freitas Siqueira Júnior ◽  
Isabela das Neves Rôças
Keyword(s):  
16S Rdna ◽  
High Sensitivity ◽  
High Specificity ◽  
Cross Reactivity ◽  
Nested Polymerase Chain Reaction ◽  
Oral Infections ◽  
Root Canals ◽  
Infected Root ◽  
Pcr Products ◽  
Species Specific

The aim of this study was to describe a 16S rDNA-based nested polymerase chain reaction (nPCR) assay to investigate the occurrence of Campylobacter gracilis in oral infections. Samples were collected from ten infected root canals, ten cases of acute periradicular abscesses and eight cases of adult marginal periodontitis. DNA extracted from the samples was initially amplified using universal 16S rDNA primers. A second round of amplification used the first PCR products to detect C. gracilis using oligonucleotide primers designed from species-specific 16S rDNA signature sequences. The nPCR assay used in this study showed a detection limit of 10 C. gracilis cells and no cross-reactivity was observed with nontarget bacteria. C. gracilis was detected in the three types of oral infections investigated - 4/10 infected root canals; 2/10 acute periradicular abscesses; and 1/8 subgingival specimens from adult periodontitis. The method proposed in this study showed both high sensitivity and high specificity to directly detect C. gracilis in samples from root canal infections, abscesses, and subgingival plaque. Our findings confirmed that C. gracilis may be a member of the microbiota associated with distinct oral infections, and its specific role in such diseases requires further clarification.

scholarly journals Interpretations of Antibody Responses toSalmonella enterica Serotype Enteritidis gm Flagellin in Poultry Flocks Are Enhanced by a Kinetics-Based Enzyme-Linked Immunosorbent Assay

1998 ◽  
Vol 5 (4) ◽  
pp. 550-555 ◽  
Author(s):  
Patrick L. McDonough ◽  
Richard H. Jacobson ◽  
John F. Timoney ◽  
Ahmed Mutalib ◽  
David C. Kradel ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
High Sensitivity ◽  
High Specificity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Analytical Sensitivity ◽  
Department Of Agriculture ◽  
Trace Back ◽  
Elisa Format ◽  
Commercial Poultry ◽  
Computer Controlled

ABSTRACT Many regulatory and diagnostic programs for the detection ofSalmonella enterica serotype Enteritidis infection in commercial poultry flocks have relied on rapid Pullorum agglutination tests to screen birds because of the shared antigens of S. enterica Enteritidis and S. enterica Pullorum and Gallinarum; however, the use of the enzyme-linked immunosorbent assay (ELISA) format affords better analytical sensitivity than crude agglutination tests. In this study, we adapted our earlier conventional indirect ELISA, using gm flagellin as the antigen, to a kinetics-based, computer-controlled ELISA (KELA). The KELA was used to screen for flagellin antibody from three commercial flocks: (i) a large flock involved in a U.S. Department of Agriculture trace back from a humanS. enterica Enteritidis foodborne outbreak (n = 3,209), (ii) a flock infected with the endemicS. enterica Enteritidis serotype but which also had multiple other salmonella serotypes (n = 65), and (iii) an S. enterica Pullorum-infected flock (n = 12). The first flock (S. entericaEnteritidis prevalence of 2.45% based on culture) provided a field test of the KELA and allowed the calculation of diagnostic sensitivity (D-Sn) and diagnostic specificity (D-Sp). With a cutoff of 10 (used for screening flocks [i.e., high sensitivity]), the KELA has a D-Sn of 95.2% and a D-Sp of 18.5%; with a cutoff of 140 (used in confirmatory flock testing [i.e., high specificity]), the KELA has a D-Sn of 28.0% and a D-Sp of 99.1%. We found that with a cutoff of 60 (D-Sn = 63.1%; D-Sp = 91.6%), we could eliminate reactions in the KELA caused by other non-S. enterica Enteritidis salmonellae. The KELA was also compared to two commercial rapid Pullorum tests, the Solvay (D-Sn = 94.9%; D-Sp = 55.5%) and the Vineland (D-Sn = 62.0%; D-Sp = 75.3%).

scholarly journals Performance of recombinant proteins in diagnosis and differentiation of canine visceral leishmaniasis infected and vaccinated dogs

2020 ◽  
Vol 10 (3) ◽  
pp. 165-171
Author(s):  
Ingrid E. Pereira ◽  
Kyssia P. Silva ◽  
Laura M. Menegati ◽  
Aimara C. Pinheiro ◽  
Elaine A. O. Assunção ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Recombinant Proteins ◽  
Serological Test ◽  
High Sensitivity ◽  
High Specificity ◽  
Cross Reactivity ◽  
Reservoir Host ◽  
Superior Performance ◽  
Canine Visceral Leishmaniasis ◽  
Roc Curve Analysis

AbstractControl of canine visceral leishmaniasis (CVL), a major zoonotic disease in Brazil and many other tropical and subtropical countries, remains difficult as an accurate and reliable diagnosis is still missing. In endemic regions, infected dogs are the main parasitic reservoir host of human Visceral leishmaniasis (VL) infection. Vaccination of dogs against Leishmania infection constitutes an important strategy to prevent or to better control CVL, thus, a serological test that can discriminate between antibodies induced by immunization versus infection is highly desirable in order to improve and simplify diagnosis. Here, four recombinant proteins were evaluated for their ability to detect and differentiate between dogs that are infected with Leishmania or have been immunized with the anti-Leishmania vaccine Leish-Tec®. Receiver operating characteristic (ROC) curve analysis of the four Leishmania-specific IgG ELISA revealed superior performance of rK28, followed by rKLO8, rK39 and rLb6H. The rK28-based ELISA revealed not only the best accuracy against CVL, but also the lowest cross-reactivity with sera from Leish-Tec® immunized dogs. Our data show that the rK28-based ELISA is highly suitable for CVL screening as it shows high sensitivity with simultaneous low cross-reactivity. Further, the high specificity of the rKLO8 indicates its suitability for the confirmation of CVL diagnosis.

Serum Adsorption Study to Validate the Specificity of a Rapid Test to Detect Strongyloides stercoralis Infection

2021 ◽  
Author(s):  
Rahmah Noordin ◽  
Emelia Osman ◽  
Nor Suhada Anuar ◽  
Nor Mustaiqazah Juri ◽  
Anizah Rahumatullah ◽  
...  
Keyword(s):  
Small Sample Size ◽  
Rapid Test ◽  
High Specificity ◽  
Strongyloides Stercoralis ◽  
Cross Reactivity ◽  
Small Sample ◽  
Polystyrene Microspheres ◽  
Diagnostic Specificity ◽  
Serum Samples ◽  
Rapid Tests

A lateral flow rapid test for strongyloidiasis will greatly facilitate the control and elimination of the disease. Previously SsRapid™ prototype rapid test showed high diagnostic specificity to detect Strongyloides infection, determined using non-Strongyloides sera negative by IgG-ELISAs. Since high specificity is crucial before a test is used for public health control activities, further validation of its specificity is needed. Also, it needs to be ascertained whether non-Strongyloides sera positive by IgG-ELISAs and SsRapid are truly positive for Strongyloides or are cases of cross-reactivity. We performed 84 rapid tests (two types of dipsticks and cassettes) using 34 serum samples. They were divided into four groups based on Strongyloides infection and coinfection with other parasites and the availability of recombinant proteins and rapid tests for the latter. Sera was adsorbed using polystyrene microspheres beads separately coated with four recombinant parasite proteins. The small sample size is a limitation of this study; however, the overall results showed that the sera adsorption procedure was successful, and the SsRapid test is specific.

scholarly journals In-house ELISA method to analyze anti-Trypanosoma cruzi IgG reactivity for differential diagnosis and evaluation of Chagas disease morbidity

2012 ◽  
Vol 45 (1) ◽  
pp. 35-44 ◽  
Author(s):  
Lilian da Silva Santos ◽  
Rosália Morais Torres ◽  
Girley Francisco Machado-de-Assis ◽  
Maria Terezinha Bahia ◽  
Helen Rodrigues Martins ◽  
...  
Keyword(s):  
Differential Diagnosis ◽  
Chagas Disease ◽  
Clinical Status ◽  
High Specificity ◽  
Disease Diagnosis ◽  
Cross Reactivity ◽  
Serological Method ◽  
Serum Dilution ◽  
Specificity And Sensitivity ◽  
American Tegumentary Leishmaniasis

INTRODUCTION: The goal was to develop an in-house serological method with high specificity and sensitivity for diagnosis and monitoring of Chagas disease morbidity. METHODS: With this purpose, the reactivities of anti-T. cruzi IgG and subclasses were tested in successive serum dilutions of patients from Berilo municipality, Jequitinhonha Valley, Minas Gerais, Brazil. The performance of the in-house ELISA was also evaluated in samples from other relevant infectious diseases, including HIV, hepatitis C (HCV), syphilis (SYP), visceral leishmaniasis (VL), and American tegumentary leishmaniasis (ATL), and noninfected controls (NI). Further analysis was performed to evaluate the applicability of this in-house methodology for monitoring Chagas disease morbidity into three groups of patients: indeterminate (IND), cardiac (CARD), and digestive/mixed (DIG/Mix), based on their clinical status. RESULTS: The analysis of total IgG reactivity at serum dilution 1:40 was an excellent approach to Chagas disease diagnosis (100% sensitivity and specificity). The analysis of IgG subclasses showed cross-reactivity, mainly with NI, VL, and ATL, at all selected serum dilutions. Based on the data analysis, the IND group displayed higher IgG3 levels and the DIG/Mix group presented higher levels of total IgG as compared with the IND and CARD groups. CONCLUSIONS: These findings demonstrated that methodology presents promising applicability in the analysis of anti-T. cruzi IgG reactivity for the differential diagnosis and evaluation of Chagas disease morbidity.

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