scholarly journals Development of an Immunochromatographic Test Strip for Detection of Cholera Toxin

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Eiki Yamasaki ◽  
Ryuta Sakamoto ◽  
Takashi Matsumoto ◽  
Fumiki Morimatsu ◽  
Takayuki Kurazono ◽  
...  
Keyword(s):  
Detection Limit ◽  
Cholera Toxin ◽  
False Positive ◽  
Culture Supernatant ◽  
Polyclonal Antibodies ◽  
High Specificity ◽  
Test Strip ◽  
Immunochromatographic Test ◽  
Positive Signal ◽  
False Positive Signal

Because cholera toxin (CT) is responsible for most of the symptoms induced byVibrio choleraeinfection, detection of CT is critical for diagnosis of the disease. In this study, we constructed an immunochromatographic test strip for detection of CT (CT-IC) with polyclonal antibodies developed against purified recombinant whole CT protein. The detection limit of the CT-IC was 10 ng/mL of purified recombinant CT, and it could detect the CT in culture supernatant of all 15 toxigenicV. choleraeisolates examined, whereas no false-positive signal was detected in all 5 nontoxigenicV. choleraeisolates examined. The specificity of the CT-IC was examined with recombinant heat-labile toxin (LT), which shares high homology with CT, and it was revealed that the minimum detection limit for LT was 100 times higher than that for CT. In addition,ltgene-positive enterotoxigenicEscherichia coli(ETEC) was examined by CT-IC. The false-positive signals were observed in 3 out of 12 ETEC isolates, but these signals were considerably faint. The CT-IC did not develop false-positive signals with all 7V. parahaemolyticusisolates. These results showed the high specificity of CT-IC and the feasible use of it for the detection and surveillance of toxigenicV. cholerae.

T7 exo-mediated FRET-breaking combined with DSN–RNAse–TdT for the detection of microRNA with ultrahigh signal-amplification

The Analyst ◽  
2019 ◽  
Vol 144 (10) ◽  
pp. 3216-3220 ◽  
Author(s):  
Van Thang Nguyen ◽  
Binh Huy Le ◽  
Young Jun Seo
Keyword(s):  
False Positive ◽  
Signal Amplification ◽  
High Sensitivity ◽  
Positive Signal ◽  
False Positive Signal ◽  
Breaking Mechanism ◽  
Very High

A DSN–RNAse–TdT–T7 exo probing system allows the detection of miRNA 21 with very high sensitivity (LOD = 2.57 fM) and selectivity—the result of (i) avoiding the false-positive signal from miRNA reacting with TdT polymerase and (ii) signal amplification occurring through a FRET-breaking mechanism involving T7 exo.

False positive signal-averaged electrocardiogram produced by atrial flutter

1990 ◽  
Vol 120 (3) ◽  
pp. 698-699 ◽  
Author(s):  
Stanley S. Schrem ◽  
Mark Nachamie ◽  
Edwin Weiss
Keyword(s):  
Atrial Flutter ◽  
False Positive ◽  
Positive Signal ◽  
False Positive Signal

Investigation of an Adventitious Agent Test False Positive Signal in a Plant-Derived Influenza Vaccine

2018 ◽  
Vol 17 ◽  
Author(s):  
Todd Talarico ◽  
Michael Murphy ◽  
Raymond Nims ◽  
Dan Hastings ◽  
Jeri Ann Boose ◽  
...  
Keyword(s):  
Influenza Vaccine ◽  
False Positive ◽  
Positive Signal ◽  
False Positive Signal

Optimal late potential criteria for reducing false positive signal-averaged electrocardiograms

1992 ◽  
Vol 123 (2) ◽  
pp. 412-416 ◽  
Author(s):  
Debra K. Moser ◽  
William G. Stevenson ◽  
Mary A. Woo
Keyword(s):  
False Positive ◽  
Positive Signal ◽  
False Positive Signal ◽  
Late Potential

False positive signal-averaged ECG produced by junctional rhythm with retrograde P waves

1992 ◽  
Vol 123 (6) ◽  
pp. 1701-1703 ◽  
Author(s):  
Eric Taylor ◽  
Mark Effron ◽  
Enrico P. Veltri
Keyword(s):  
False Positive ◽  
Positive Signal ◽  
P Waves ◽  
Junctional Rhythm ◽  
False Positive Signal

Detection of Cholera Toxin by an Immunochromatographic Test Strip

2017 ◽  
pp. 1-7 ◽  
Author(s):  
Eiki Yamasaki ◽  
Ryuta Sakamoto ◽  
Takashi Matsumoto ◽  
Biswajit Maiti ◽  
Kayo Okumura ◽  
...  
Keyword(s):  
Cholera Toxin ◽  
Test Strip ◽  
Immunochromatographic Test

scholarly journals How to Improve Sensitivity of Sandwich Lateral Flow Immunoassay for Corpuscular Antigens on the Example of Potato Virus Y?

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3975 ◽  
Author(s):  
Shyatesa Razo ◽  
Vasily Panferov ◽  
Irina Safenkova ◽  
Yuri Varitsev ◽  
Anatoly Zherdev ◽  
...  
Keyword(s):  
Detection Limit ◽  
Potato Virus ◽  
Potato Virus Y ◽  
Polyclonal Antibodies ◽  
Test Strip ◽  
Lateral Flow ◽  
Lateral Flow Immunoassay ◽  
Enzyme Linked Immunosorbent Assay ◽  
Quantitative Results ◽  
Solanaceae Family

A simple approach was proposed to decrease the detection limit of sandwich lateral flow immunoassay (LFIA) by changing the conditions for binding between a polyvalent antigen and a conjugate of gold nanoparticles (GNPs) with antibodies. In this study, the potato virus Y (PVY) was used as the polyvalent antigen, which affects economically important plants in the Solanaceae family. The obtained polyclonal antibodies that are specific to PVY were characterized using a sandwich enzyme-linked immunosorbent assay (ELISA) and surface plasmon resonance (SPR). For LFIA, the antibodies were conjugated with GNPs with a diameter of 17.4 ± 1.0 nm. We conducted LFIAs using GNP conjugates in a dried state on the test strip and after pre-incubation with a sample. Pre-incubating the GNP conjugates and sample for 30 s was found to decrease the detection limit by 60-fold from 330 ng∙mL−1 to 5.4 ng∙mL−1 in comparison with conventional LFIA. The developed method was successfully tested for its ability to detect PVY in infected and uninfected potato leaves. The quantitative results of the proposed LFIA with pre-incubation were confirmed by ELISA, and resulted in a correlation coefficient of 0.891. The proposed approach is rapid, simple, and preserves the main advantages of LFIA as a non-laboratory diagnostic method.

Overcoming multimeric target interference in a bridging immunogenicity assay with soluble target receptor, target immunodepletion and mild acidic assay pH

Bioanalysis ◽  
2020 ◽  
Vol 12 (15) ◽  
pp. 1071-1085
Author(s):  
Jihua Chen ◽  
Kimberly Kendra ◽  
Albert Torri ◽  
Giane Sumner
Keyword(s):  
False Positive ◽  
Magnetic Beads ◽  
Positive Signal ◽  
Background Signal ◽  
Serum Samples ◽  
Post Dose ◽  
High Background ◽  
False Positive Signal ◽  
Acidic Conditions ◽  
Immunogenicity Assay

Background: Soluble multimeric target proteins can generate a target-mediated false-positive signal in bridging anti-drug antibody (ADA) assays. A high background signal due to target interference was observed in our anti-REGN-Y antibody assay, and two different strategies were evaluated to mitigate this false-positive signal. Results: Multiple anti-target antibodies were tested and found to be ineffective at reducing target interference, so soluble target receptor and co-factor proteins were used in combination to inhibit the target-mediated signal. These competitive blockers synergistically inhibited target interference and increased target tolerance levels, especially when the assay was performed under mild acidic conditions. A separate approach, target immunodepletion using magnetic beads conjugated with an anti-target antibody, was also effective at mitigating the target-mediated signal, also in combination with mild acidic assay pH. Both methods allowed detection of a true ADA signal in monkey and human post-dose serum samples. Conclusion: These methods provide alternative strategies for mitigating target interference when standard anti-target antibodies are ineffective, with the competitive blocker method being recommended, if possible, due to its higher throughput and easier execution.

Determination of Ochratoxin A in Feed by Immunoaffinity Cleanup and Liquid Chromatography

2013 ◽  
Vol 96 (3) ◽  
pp. 599-602 ◽  
Author(s):  
Ping Ding ◽  
Ziyou Mi ◽  
Yali Hou ◽  
Yigang He ◽  
Jianhua Xie
Keyword(s):  
Liquid Chromatography ◽  
Detection Limit ◽  
Ochratoxin A ◽  
Cyanogen Bromide ◽  
Polyclonal Antibodies ◽  
Immunoaffinity Column ◽  
Low Levels ◽  
Sepharose 4B ◽  
Feed Samples

Abstract A method using LC was developed for determination of ochratoxin A (OTA) in feeds. The extracted samples were cleaned up by an immunoaffinity column prepared by covalently coupling polyclonal antibodies against OTA to cyanogen bromide-activated Sepharose 4B. The eluates were determined by LC with fluorescence detection. Recoveries of OTA from fortified samples of 1–10 μg/kg levels ranged from 84.3 to 90.0%, with CVs of 3.3–7.8%. The detection limit was 0.045 μg/kg based on an S/N of 3:1. A total of 65 feed samples were screened for OTA with the proposed method. The results showed that only nine samples were contaminated with OTAs at low levels. The presented method was successfully applied to quantify OTAs in real feed samples.

Simultaneous detection of phenacetin and its metabolite using a gold nanoparticle-based immunochromatographic test strip

The Analyst ◽  
2021 ◽  
Author(s):  
Jingjing Yao ◽  
Xin-Xin Xu ◽  
Liqiang Liu ◽  
Hua Kuang ◽  
Zhengyou Wang ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Gold Nanoparticle ◽  
Simultaneous Detection ◽  
Test Strip ◽  
Immunochromatographic Test ◽  
Immunochromatographic Strip

We have developed a sensitive and rapid gold nanoparticle-based immunochromatographic strip (GNP-ICS) for the detection of phenacetin (PNCT) using an anti-PNCT monoclonal antibody (mAb). The specific anti- PNCT mAb (2D6)...

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