scholarly journals An effective strategy for preparation of a polyclonal antibody with an addition of carbon chain of ciprofloxacin

2018 ◽  
Vol 16 ◽  
pp. 205873921880564
Author(s):  
Dong Wei ◽  
Guozhen Fang ◽  
Shuo Wang
Keyword(s):  
Polyclonal Antibody ◽  
Limit Of Detection ◽  
High Titer ◽  
Carbon Chain ◽  
Cross Reactivity ◽  
Carrier Protein ◽  
Effective Strategy ◽  
Coating Antigen ◽  
Spacer Arm ◽  
Proper Modification

In this study, we synthesized amino propyl ciprofloxacin (CPLX-NH2) as a ciprofloxacin (CPLX) derivative. Moreover, the immune antigen CPLX-NH2-BSA and coating antigen CPLX-NH2-OVA were prepared via CPLX-NH2 coupling with bovine serum albumin (BSA) and ovalbumin (OVA), respectively. Subsequently, the Kunming mice were immunized with immune antigen to obtain the polyclonal antibody with high titer. The regression equation of CPLX-NH2 antibody was y = –17.395x + 89.331 (R2 = 0.9961); IC50 and limit of detection (LOD) were 182.39 and 20.09 ng/mL, respectively. These results were superior to that of CPLX antibody. Meanwhile, the CPLX-NH2 antibody showed cross-reactivity to fluoroquinolones (FQNs) residues. The results of the study indicated that the proper modification of the drug, namely, the addition of a suitable spacer arm between the drug and the carrier protein will improve the efficacy of the antibody, which is a favorable concept for preparation of antibody.

Detection of Zearalenone by Chemiluminescence Immunoassay in Corn Samples

2012 ◽  
Vol 550-553 ◽  
pp. 1911-1914 ◽  
Author(s):  
Yuan Kai Wang ◽  
Qi Zou ◽  
Jian He Sun ◽  
Heng An Wang ◽  
Ya Xian Yan
Keyword(s):  
Polyclonal Antibody ◽  
Limit Of Detection ◽  
Detection Methods ◽  
Optimum Conditions ◽  
Reaction Conditions ◽  
Chemiluminescence Immunoassay ◽  
Coating Antigen ◽  
Elisa Kit ◽  
Mouse Antibody ◽  
Good Agreement

A chemiluminescence immunoassay with polyclonal antibody for detecting zearalenone in corn samples was developed. The optimized reaction conditions include the concentration of coating antigen (0.253 μg/ml), the polyclonal antibody (1:7500) and HRP labeled goat anti-mouse antibody (1:40000), the competition time (60 min), pH of dilution buffer (7.4), the concentration of methanol (10%) and the ratio of luminol to ρ-iodophenol (2:5) were all investigated. Based on optimum conditions, the chemoluminscence ELISA detect range was f 0.05 - 54.34 ng/ml, with IC50 was 2.93 ng/ml, and the limit of detection was 0.02 ng/ml. The chemiluminescence immunoassay shows a good agreement with commercial ELISA kit for detection zearalenone in the spiked samples. The chemiluminescence immunoassay is easier in pretreating, and more sensitive when compared with other detection methods include chromatography methods and immunoassays.

scholarly journals Antibody responses to endemic coronaviruses modulate COVID-19 convalescent plasma functionality

2020 ◽  
Author(s):  
William Morgenlander ◽  
Stephanie Henson ◽  
Daniel Monaco ◽  
Athena Chen ◽  
Kirsten Littlefield ◽  
...  
Keyword(s):  
Polyclonal Antibody ◽  
Strong Correlation ◽  
Neutralizing Antibodies ◽  
High Titer ◽  
Fusion Peptide ◽  
Cross Reactivity ◽  
Antibody Responses ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Human Coronavirus

AbstractCOVID-19 convalescent plasma, particularly plasma with high-titer SARS-CoV-2 (CoV2) antibodies, has been successfully used for treatment of COVID-19. The functionality of convalescent plasma varies greatly, but the association of antibody epitope specificities with plasma functionality remains uncharacterized. We assessed antibody functionality and reactivities to peptides across the CoV2 and the four endemic human coronavirus (HCoV) genomes in 126 COVID-19 convalescent plasma donations. We found strong correlation between plasma functionality and polyclonal antibody targeting of CoV2 spike protein peptides. Antibody reactivity to many HCoV spike peptides also displayed strong correlation with plasma functionality, including pan-coronavirus cross-reactive epitopes located in a conserved region of the fusion peptide. After accounting for antibody cross-reactivity, we identified an association between greater alphacoronavirus NL63 antibody responses and development of highly neutralizing antibodies to SARS-CoV-2. We also found that plasma preferentially reactive to the CoV2 receptor binding domain (RBD), versus the betacoronavirus HKU1 RBD, had higher neutralizing titer. Finally, we developed a two-peptide serosignature that identifies plasma donations with high anti-S titer but that suffer from low neutralizing activity. These results suggest that analysis of coronavirus antibody fine specificities may be useful for selecting therapeutic plasma with desired functionalities.

scholarly journals Subtractive inhibition assay for the detection of Campylobacter jejuni in chicken samples using surface plasmon resonance

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Noor Azlina Masdor ◽  
Zeynep Altintas ◽  
Mohd. Yunus Shukor ◽  
Ibtisam E. Tothill
Keyword(s):  
Surface Plasmon Resonance ◽  
Campylobacter Jejuni ◽  
Surface Plasmon ◽  
Polyclonal Antibody ◽  
Plasmon Resonance ◽  
Limit Of Detection ◽  
High Specificity ◽  
Cross Reactivity ◽  
Inhibition Assay ◽  
Infectious Dose

Abstract In this work, a subtractive inhibition assay (SIA) based on surface plasmon resonance (SPR) for the rapid detection of Campylobacter jejuni was developed. For this, rabbit polyclonal antibody with specificity to C. jejuni was first mixed with C. jejuni cells and unbound antibody was subsequently separated using a sequential process of centrifugation and then detected using an immobilized goat anti-rabbit IgG polyclonal antibody on the SPR sensor chip. This SIA-SPR method showed excellent sensitivity for C. jejuni with a limit of detection (LOD) of 131 ± 4 CFU mL−1 and a 95% confidence interval from 122 to 140 CFU mL−1. The method has also high specificity. The developed method showed low cross-reactivity to bacterial pathogens such as Salmonellaenterica serovar Typhimurium (7.8%), Listeria monocytogenes (3.88%) and Escherichia coli (1.56%). The SIA-SPR method together with the culturing (plating) method was able to detect C. jejuni in the real chicken sample at less than 500 CFU mL−1, the minimum infectious dose for C. jejuni while a commercial ELISA kit was unable to detect the bacterium. Since the currently available detection tools rely on culturing methods, which take more than 48 hours to detect the bacterium, the developed method in this work has the potential to be a rapid and sensitive detection method for C. jejuni.

scholarly journals Examination of the Efficacy and Cross-Reactivity of a Novel Polyclonal Antibody Targeting the Disintegrin Domain in SVMPs to Neutralize Snake Venom

Toxins ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 254
Author(s):  
Shelby S. Szteiter ◽  
Ilse N. Diego ◽  
Jonathan Ortegon ◽  
Eliana Salinas ◽  
Abcde Cirilo ◽  
...  
Keyword(s):  
Snake Venom ◽  
Polyclonal Antibody ◽  
Polyclonal Antibodies ◽  
Cross Reactivity ◽  
Snake Envenomation ◽  
Disintegrin Domain ◽  
The Common ◽  
Neutralization Ability ◽  
New Strategies

Snake envenomation can result in hemorrhage, local necrosis, swelling, and if not treated properly can lead to adverse systemic effects such as coagulopathy, nephrotoxicity, neurotoxicity, and cardiotoxicity, which can result in death. As such, snake venom metalloproteinases (SVMPs) and disintegrins are two toxic components that contribute to hemorrhage and interfere with the hemostatic system. Administration of a commercial antivenom is the common antidote to treat snake envenomation, but the high-cost, lack of efficacy, side effects, and limited availability, necessitates the development of new strategies and approaches for therapeutic treatments. Herein, we describe the neutralization ability of anti-disintegrin polyclonal antibody on the activities of isolated disintegrins, P-II/P-III SVMPs, and crude venoms. Our results show disintegrin activity on platelet aggregation in whole blood and the migration of the SK-Mel-28 cells that can be neutralized with anti-disintegrin polyclonal antibody. We characterized a SVMP and found that anti-disintegrin was also able to inhibit its activity in an in vitro proteolytic assay. Moreover, we found that anti-disintegrin could neutralize the proteolytic and hemorrhagic activities from crude Crotalus atrox venom. Our results suggest that anti-disintegrin polyclonal antibodies have the potential for a targeted approach to neutralize SVMPs in the treatment of snakebite envenomations.

Two Enzyme Immunoassays to Screen for 2,4-Dichlorophenoxyacetic Acid in Water

1987 ◽  
Vol 70 (5) ◽  
pp. 874-878 ◽  
Author(s):  
James Fleeker
Keyword(s):  
Limit Of Detection ◽  
Solid Phase ◽  
Dichlorophenoxyacetic Acid ◽  
Carrier Protein ◽  
Similar Response ◽  
Enzyme Immunoassays ◽  
Concentration Step ◽  
Chlorophenoxyacetic Acid ◽  
Phenoxy Herbicides ◽  
2,4 Dichlorophenoxyacetic Acid

Abstract Two solid-phase enzyme immunoassays were developed to measure 2,4-dichlorophenoxyacetic acid (2,4-D), using 2 sets of structurally distinct immunogens and enzyme ligands. The 2,4-D analog, 2-methyl- 4-chlorophenoxyacetic acid (MCPA), gave a similar response with both methods, whereas other phenoxy herbicides cross-reacted differently. In method A, the aromatic moiety of 2,4-D was distal from the carrier protein and labeled enzyme, whereas in method B, the acetic acid portion of the herbicide was distal. The use of both methods to screen for this herbicide in ground water and municipal and river water reduced the number of false-positive responses. Water sources having a low background response could be monitored with either method alone. When a concentration step, with disposable C18 extraction columns, was used, the limit of sensitivity was 5 ng/L,. Method A was the more sensitive of the 2 methods with a limit of detection of 10 j*g/L without the concentration step

Evaluation of an alternative S100b assay for use in cardiac surgery: relationship with microemboli and neuropsychological outcome

Perfusion ◽  
2007 ◽  
Vol 22 (4) ◽  
pp. 267-272 ◽  
Author(s):  
D.C. Whitaker ◽  
A.J.E. Green ◽  
J. Stygall ◽  
M.J.G. Harrison ◽  
S.P. Newman
Keyword(s):  
Cardiac Surgery ◽  
Limit Of Detection ◽  
Artery Bypass ◽  
Sandwich Elisa ◽  
High Sensitivity ◽  
Cross Reactivity ◽  
Cell Protein ◽  
Skin Closure ◽  
Neuropsychological Outcome ◽  
The Right

Introduction. The aim of the study was to investigate the relationship between S100b release, neuropsychological outcome and cerebral microemboli. Peri-operative assay of the astroglial cell protein S100b has been used as a marker of cerebral damage after cardiac surgery but potential assay cross-reactivity has limited its specificity. The present study uses an alternative enzyme-linked immunoabsorbant assay (ELISA) for serum S100b that has documented sensitivity and specificity data in patients undergoing coronary artery bypass grafting (CABG). Methods. Fifty-five consecutive patients undergoing routine CABG surgery received serial venous S100b sampling at five time points: i) Pre-operative, ii) At the end of cardiopulmonary bypass (CPB), iii) 6 hrs, iv) 24 hrs and v) 48 hrs post skin closure. A previously described sandwich ELISA with monoclonal anti- S100b was used. This assay has a lower limit of detection of 0.04 μ g/L and < 0.006% reactivity with S100a at a concentration of 100 μg/L S100a. Cerebral microemboli during surgery were recorded by transcranial Doppler monitor over the right middle cerebral artery. Evidence of cerebral impairment was obtained by comparing patients' performance in a neuropsychological battery of 9 tests administered 6—8 weeks post-operatively with their pre-operative scores. Results. There was a significant increase in S100b only at the end of bypass (mean 0.30 μg/L, SD ± 0.33 and range .00 to 1.57). S100b levels at the end of bypass did not correlate with neuropsychological outcome or microemboli counts. Conclusions. The low levels of S100b detected using the present assay, despite its high sensitivity and despite the routine use of cardiotomy suction, suggest that the assay may have higher specificity for cerebral S100b than previously used assays. There was no evidence that this assay is related to neuropsychological change or cerebral microemboli in cardiac surgery. Perfusion (2007) 22, 267—272.

scholarly journals Selection and Identification of Novel Aptamers Specific for Clenbuterol Based on ssDNA Library Immobilized SELEX and Gold Nanoparticles Biosensor

Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2337 ◽  
Author(s):  
Xixia Liu ◽  
Qi Lu ◽  
Sirui Chen ◽  
Fang Wang ◽  
Jianjun Hou ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
High Throughput ◽  
High Throughput Sequencing ◽  
Limit Of Detection ◽  
Retention Rate ◽  
Pcr Amplification ◽  
Cross Reactivity ◽  
Enriched Library ◽  
Amplification Curve ◽  
Specificity And Sensitivity

We describe a multiple combined strategy to discover novel aptamers specific for clenbuterol (CBL). An immobilized ssDNA library was used for the selection of specific aptamers using the systematic evolution of ligands by exponential enrichment (SELEX). Progress was monitored using real-time quantitative PCR (Q-PCR), and the enriched library was sequenced by high-throughput sequencing. Candidate aptamers were picked and preliminarily identified using a gold nanoparticles (AuNPs) biosensor. Bioactive aptamers were characterized for affinity, circular dichroism (CD), specificity and sensitivity. The Q-PCR amplification curve increased and the retention rate was about 1% at the eighth round. Use of the AuNPs biosensor and CD analyses determined that six aptamers had binding activity. Affinity analysis showed that aptamer 47 had the highest affinity (Kd = 42.17 ± 8.98 nM) with no cross reactivity to CBL analogs. Indirect competitive enzyme linked aptamer assay (IC-ELAA) based on a 5′-biotin aptamer 47 indicated the limit of detection (LOD) was 0.18 ± 0.02 ng/L (n = 3), and it was used to detect pork samples with a mean recovery of 83.33–97.03%. This is the first report of a universal strategy including library fixation, Q-PCR monitoring, high-throughput sequencing, and AuNPs biosensor identification to select aptamers specific for small molecules.

Development of a Surface Plasmon Resonance–Based Immunoassay for Listeria monocytogenes

2005 ◽  
Vol 68 (4) ◽  
pp. 728-735 ◽  
Author(s):  
PAUL LEONARD ◽  
STEPHEN HEARTY ◽  
GARY WYATT ◽  
JOHN QUINN ◽  
RICHARD O'KENNEDY
Keyword(s):  
Surface Plasmon Resonance ◽  
Listeria Monocytogenes ◽  
Surface Plasmon ◽  
Polyclonal Antibody ◽  
Plasmon Resonance ◽  
Limit Of Detection ◽  
Chip Surface ◽  
Metal Affinity ◽  
Coefficients Of Variation ◽  
Internalin B

A polyclonal antibody was produced against Internalin B (InlB)–enriched extract and used to develop an inhibition assay to detect Listeria monocytogenes cells in solution using surface plasmon resonance. The gene sequence encoding for the InlB protein was cloned into a Qiagen pQE-60 vector, expressed in Escherichia coli, and purified by immobilized metal affinity chromatography. Protein G–purified anti-InlB–enriched extract polyclonal antibody was incubated with various concentrations of L. monocytogenes cells and subsequently injected over a purified-recombinant InlB (rInlB)–immobilized CM5 sensor chip surface. A decrease in antibody binding response was observed with increasing L. monocytogenes cell concentrations. Intraday and interday assay variability studies were carried out to evaluate precision and reproducibility. The assay had a limit of detection of less than 2 × 105 cells per ml and could be successfully reproduced with coefficients of variation of between 2.5 and 7.7%.

scholarly journals Rapid immunoassays for detection of anabolic nortestosterone in dietary supplements

2013 ◽  
Vol 31 (No. 5) ◽  
pp. 514-519 ◽  
Author(s):  
B. Holubová ◽  
S. Göselová ◽  
L. Ševčíková ◽  
M. Vlach ◽  
M. Blažková ◽  
...  
Keyword(s):  
Dietary Supplements ◽  
Rapid Detection ◽  
Visual Detection ◽  
Limit Of Detection ◽  
Polyclonal Antibodies ◽  
Cross Reactivity ◽  
Rapid Analysis ◽  
Experimental Conditions ◽  
Immunochromatographic Strip ◽  
Strip Test

An enzyme immunoassay (ELISA) and an immunochromatographic strip were designed for a rapid detection of nortestosterone in dietary supplements. Two polyclonal antibodies and two types of nortestosterone-protein coating conjugates were tested to develop the most appropriate method. Under optimal experimental conditions, the most sensitive ELISA achieved the IC<sub>50 </sub>and the limit of detection values of 6.41 and 0.09 ng/ml, respectively. The assay specificity was tested measuring cross-reactivity of several steroids. The interference with the assay was negligible (&lt; 0.1%), except for cross-reactivity with another frequently abused steroid testosterone (23%). The optimised gold particle-based immunochromatographic strip provided in semi-quantitative test a visual detection limit of 1&nbsp;ng/ml. None of these methods showed the interference using a filtrate of the suspension of non-contaminated sample. After the validation for particular matrices, the ELISA and the strip test could be useful tools for a rapid analysis of nortestosterone in crude extracts of dietary supplements.

scholarly journals Molecularly Imprinted Nanoparticles Based Sensor for Cocaine Detection

Biosensors ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 22 ◽  
Author(s):  
Roberta D’Aurelio ◽  
Iva Chianella ◽  
Jack A. Goode ◽  
Ibtisam E. Tothill
Keyword(s):  
Electrochemical Impedance ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Cost Effective ◽  
Cross Reactivity ◽  
P Value ◽  
Sensing Element ◽  
Molecularly Imprinted ◽  
Cost Effective Method ◽  
Cocaine Detection

The development of a sensor based on molecularly imprinted polymer nanoparticles (nanoMIPs) and electrochemical impedance spectroscopy (EIS) for the detection of trace levels of cocaine is described in this paper. NanoMIPs for cocaine detection, synthesized using a solid phase, were applied as the sensing element. The nanoMIPs were first characterized by Transmission Electron Microscopy (TEM) and Dynamic Light Scattering and found to be ~148.35 ± 24.69 nm in size, using TEM. The nanoMIPs were then covalently attached to gold screen-printed electrodes and a cocaine direct binding assay was developed and optimized, using EIS as the sensing principle. EIS was recorded at a potential of 0.12 V over the frequency range from 0.1 Hz to 50 kHz, with a modulation voltage of 10 mV. The nanoMIPs sensor was able to detect cocaine in a linear range between 100 pg mL−1 and 50 ng mL−1 (R2 = 0.984; p-value = 0.00001) and with a limit of detection of 0.24 ng mL−1 (0.70 nM). The sensor showed no cross-reactivity toward morphine and a negligible response toward levamisole after optimizing the sensor surface blocking and assay conditions. The developed sensor has the potential to offer a highly sensitive, portable and cost-effective method for cocaine detection.

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