Highly Specific Chemiluminescence Immunoassay for the Determination of Chloramphenicol in Cosmetics

A direct and highly specific chemiluminescent enzyme-linked immunosorbent assay (CL-ELISA) method for monitoring chloramphenicol (CAP) in cosmetics has been developed. The anti-chloramphenicol antibody (mAb) adopted in this work for direct immunoassay could bind to CAP specifically, with negligible cross-reactivity (CR) (less than 0.01%) with most CAP analogues, including structurally related thiamphenicol (TAP) and florfenicol (FF). The limit of detection (LOD), measured by IC10, was 0.0021 ng mL−1. The detection range (IC20-IC80) was ranged from 0.00979 to 0.12026 ng mL−1. In spiked cosmetics samples, mean recoveries ranged from 82.7% to 99.6%, with intraday and interday variation less than 9.8 and 8.2%, respectively. Moreover, with the help of HRP-labeled anti-CAP mAb, the method could be processed in fast direct immunoreaction mode. This CL-ELISA method could be applied for specific, rapid, semiquantitative, and quantitative detection of CAP in cosmetics, facilitating the precise quality control of CAP contamination.

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Diarrhetic Shellfish Poisoning: Evaluation of Enzyme-Linked Immunosorbent Assay Methods for Determination of Dinophyslstoxin-2

Journal of AOAC International ◽

10.1093/jaoac/78.6.1403 ◽

1995 ◽

Vol 78 (6) ◽

pp. 1403-1407 ◽

Cited By ~ 7

Author(s):

Eoin P Carmody ◽

Kevin J James ◽

Seán S Kelly

Keyword(s):

Immunosorbent Assay ◽

Cross Reactivity ◽

Regulatory Control ◽

Enzyme Linked Immunosorbent Assay ◽

Shellfish Poisoning ◽

Diarrhetic Shellfish Poisoning ◽

Elisa Method ◽

Multiple Samples ◽

Liquid Chromatographic

Abstract Dinophysistoxin-2 (DTX-2), an isomer of okadaic acid (OA), recently has been found in Irish waters. DTX-2 was the predominant toxin during prolonged infestations in cultivated mussels along the southwest coast of Ireland. Substantial variations in toxin levels may exist both horizontally and vertically in the water column. The need to take multiple samples and the ethical concern about the use of mammals for routine quality control of shellfish prompted examination of 2 commercially available enzyme-linked immunosorbent assay (ELISA) methods, designed to detect OA, for determination of both OA and DTX-2. One ELISA method (DSPCheck, Sceti Co. Ltd., (Tokyo, Japan) showed good cross-reactivity (40 ± 5%) with standard DTX-2. This study showed that both ELISA methods show good correlation with the liquid chromatographic analysis of 9-anthryldiazomethane derivatives when OA is the predominant toxin present. The sensitivity was also good for OA determination using both methods, which allowed toxin measurement at 10 ng/mL (0.5 ng/well). This level is equivalent to 0.03 μg/g mussel meat. Blank mussel samples spiked with DTX-2 standards gave a good linear correlation (r = 0.997) with this ELISA method when toxin levels were 0.03-0.3 μg/g mussel meat. This range is appropriate for regulatory control of diarrhetic shellfish poisoning.

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Single-Laboratory Validation of the Biosense Direct Competitive Enzyme-Linked Immunosorbent Assay (ELISA) for Determination of Domoic Acid Toxins in Shellfish

Journal of AOAC International ◽

10.1093/jaoac/90.4.1000 ◽

2007 ◽

Vol 90 (4) ◽

pp. 1000-1010 ◽

Cited By ~ 9

Author(s):

Hans Kleivdal ◽

Sven-Inge Kristiansen ◽

Mona V Nilsen ◽

Lyn Briggs

Keyword(s):

Immunosorbent Assay ◽

Domoic Acid ◽

Matrix Effects ◽

Limit Of Detection ◽

Method Comparison ◽

Cross Reactivity ◽

Enzyme Linked Immunosorbent Assay ◽

Shellfish Poisoning ◽

Relative Standard

Abstract Method validation was conducted for an enzyme-linked immunosorbent assay (ELISA) for the determination of domoic acid (DA) toxins, known to give amnesic shellfish poisoning (ASP) symptoms, in shellfish. The calibration curve range of the assay is approximately 10260 pg/mL, with a dynamic working range for DA toxins in shellfish from 0.01 to at least 250 mg/kg. The ASP ELISA showed no significant cross-reactivity to structural analogs, and proved to be robust to deliberate alterations of the optimal running conditions. The shellfish matrix effects observed with mussels, oysters, and scallops were eliminated by diluting shellfish extracts 1:200 prior to analysis, leading to a limit of detection at 0.003 mg/kg. Thirteen blank shellfish homogenates were spiked with certified mussel material containing DA to levels in the range of 0.125 mg DA/kg, and analyzed in quadruplicate on 3 different days. The relative standard deviation (RSD) under intra-assay repeatability conditions ranged from 6.5 to 13.1%, and under interassay repeatability conditions the RSD ranged from 5.7 to 13.4%, with a mean value of 9.3%. The recoveries ranged from 85.5 to 106.6%, with a mean recovery of 102.2%. A method comparison was conducted with liquid chromatography with ultraviolet detection, using naturally contaminated scallop samples (n = 27) with DA levels at 0244 mg/kg. The overall correlation coefficient was 0.960 and the slope of the regression was 1.218, indicating a good agreement between the methods.

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Detection of bisphenol A in water samples using ELISA determination method

Water Science & Technology Water Supply ◽

10.2166/ws.2011.008 ◽

2011 ◽

Vol 11 (1) ◽

pp. 55-60 ◽

Cited By ~ 4

Author(s):

J. Zheng ◽

S. Q. Zhao ◽

X. T. Xu ◽

K. Zhang

Keyword(s):

Drinking Water ◽

Bisphenol A ◽

Water Samples ◽

Limit Of Detection ◽

Industrial Effluent ◽

Cross Reactivity ◽

Enzyme Linked Immunosorbent Assay ◽

Uv Spectrophotometry ◽

Inhibition Concentration

In order to study whether bisphenol A (BPA) can pass into drinking water from polycarbonate barrel and exist in the river and industrial effluent the indirect competitive enzyme-linked immunosorbent assay (ELISA) for the determination of BPA was established. The results presented an inhibition concentration at 50% absorbance (IC50) of 0.123 mg L−1, and the limit of detection (LOD) is 9.934 μg L−1. The specificity of antiserum was proved well because the cross-reactivity with benzene, tert-butylbenzene, hydroquinone and o-hydroxybenzoic acid were found lower than 0.01%, except phenol was 0.26%. The method was found to be reliable and repeatable. It was used for monitoring the concentration of BPA in the barreled drinking water. The results confirmed BPA can pass into barreled drinking water from the polycarbonate barrel and concentration increased as days went on. A certain content of BPA was found in industrial effluent. The results of ELISA were consistent with the results of UV spectrophotometry. BPA could not be found in the water samples obtained from Zhujiang River. The established method shows specific recognition of BPA and could be applied in detection of environmental BPA.

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Detection of Brevetoxin in Human Plasma by ELISA

Journal of Analytical Toxicology ◽

10.1093/jat/bkab010 ◽

2021 ◽

Author(s):

Brady R Cunningham ◽

Rebecca M Coleman ◽

Adam M Schaefer ◽

Elizabeth I Hamelin ◽

Rudolph C Johnson

Keyword(s):

Human Plasma ◽

Limit Of Detection ◽

Cross Reactivity ◽

Quantitative Detection ◽

Red Tides ◽

Plasma Samples ◽

Detection Range ◽

Paralytic Shellfish ◽

Test Kit ◽

Relative Standard

Abstract Florida red tides have become more common and persistent in and around the Gulf of Mexico. When in bloom, red tides can produce brevetoxins in high concentrations, leading to human exposures primarily through contaminated food and ocean spray. The research described here includes adapting and validating a commercial brevetoxin water test kit for human plasma testing. Pooled plasma was fortified with a model brevetoxin, brevetoxin 3, at concentrations from 0.00500 to 3.00 ng/mL to generate calibration curves and quality control samples. The quantitative detection range was determined to be 0.0400–2.00 ng/mL brevetoxin 3 equivalents with inter- and intraday accuracies ranging from 94.0% to 109% and relative standard deviations <20%, which is within the US Food and Drug Administration guidelines for receptor-binding assays. Additionally, cross-reactivity was tested using 4 of the 10 known brevetoxins and 12 paralytic shellfish toxins. The cross-reactivity varied from 0.173% to 144% for the commercially available brevetoxin standards and 0% for the commercially available paralytic shellfish toxin standards. Fifty individual unexposed human plasma samples were measured to determine the limit of detection and endogenous interferences to the test. The validated method was used to test 31 plasma samples collected from humans potentially exposed to brevetoxins, detecting 11 positives. This method has been proven useful to measure human exposure to brevetoxins and can be applied to future exposure events.

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Pitfalls in the Immunochemical Determination of β‑Lactam Antibiotics in Water

Antibiotics ◽

10.3390/antibiotics10030298 ◽

2021 ◽

Vol 10 (3) ◽

pp. 298

Author(s):

Alexander Ecke ◽

Rudolf J. Schneider

Keyword(s):

Limit Of Detection ◽

Cost Effective ◽

Enzyme Linked Immunosorbent Assay ◽

Degree Of Hydrolysis ◽

Site Analysis ◽

Antibody Recognition ◽

Immunochemical Determination ◽

Key Factor ◽

Lactam Ring

Contamination of waters with pharmaceuticals is an alarming problem as it may support the evolution of antimicrobial resistance. Therefore, fast and cost-effective analytical methods for potential on-site analysis are desired in order to control the water quality and assure the safety of its use as a source of drinking water. Antibody-based methods, such as the enzyme-linked immunosorbent assay (ELISA), can be helpful in this regard but can also have certain pitfalls in store, depending on the analyte. As shown here for the class of β-lactam antibiotics, hydrolysis of the β‑lactam ring is a key factor in the immunochemical analysis as it influences antibody recognition. With the antibody used in this study, the limit of detection (LOD) in the immunoassay could be significantly reduced by hydrolysis for the five tested penicillins, with the lowest LOD for carbenicillin (0.2 nmol/L) and the greatest impact on penicillins G and V (reduction by 85%). In addition to enhanced quantification, our strategy also provides access to information about the degree of hydrolysis in water samples as shown for the most abundant penicillin amoxicillin.

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Characterization of the Diagnostic Performance of a Novel COVID-19 PETIA in Comparison to Four Routine N-, S- and RBD-Antigen Based Immunoassays

Diagnostics ◽

10.3390/diagnostics11081332 ◽

2021 ◽

Vol 11 (8) ◽

pp. 1332

Author(s):

Alexander Spaeth ◽

Thomas Masetto ◽

Jessica Brehm ◽

Leoni Wey ◽

Christian Kochem ◽

...

Keyword(s):

Immune Response ◽

Cross Reactivity ◽

Enzyme Linked Immunosorbent Assay ◽

Chemiluminescence Immunoassay ◽

Face To Face ◽

Comprehensive Comparison ◽

Broad Variety ◽

Viral Responses ◽

Novel Coronavirus ◽

High Consistency

In 2019, a novel coronavirus emerged in Wuhan in the province of Hubei, China. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) quickly spread across the globe, causing the neoteric COVID-19 pandemic. SARS-CoV-2 is commonly transmitted by droplet infection and aerosols when coughing or sneezing, as well as high-risk exposures to infected individuals by face-to-face contact without protective gear. To date, a broad variety of techniques have emerged to assess and quantify the specific antibody response of a patient towards a SARS-CoV-2 infection. Here, we report the first comprehensive comparison of five different assay systems: Enzyme-Linked Immunosorbent Assay (ELISA), Chemiluminescence Immunoassay (CLIA), Electro-Chemiluminescence Immunoassay (ECLIA), and a new Particle-Enhanced Turbidimetric Immunoassay (PETIA) for SARS-CoV-2. Furthermore, we also evaluated the suitability of N-, S1- and RBD-antigens for quantifying the SARS-CoV-2 specific immune response. Linearity and precision, overall sensitivity and specificity of the assays, stability of samples, and cross-reactivity of general viral responses, as well as common coronaviruses, were assessed. Moreover, the reactivity of all tests to seroconversion and different sample matrices was quantified. All five assays showed good overall agreement, with 76% and 87% similarity for negative and positive samples, respectively. In conclusion, all evaluated methods showed a high consistency of results and suitability for the robust quantification of the SARS-CoV-2-derived immune response.

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Streptavidin-conjugated gold nanoclusters as ultrasensitive fluorescent sensors for early diagnosis of HIV infection

Science Advances ◽

10.1126/sciadv.aar6280 ◽

2018 ◽

Vol 4 (11) ◽

pp. eaar6280 ◽

Cited By ~ 15

Author(s):

Aditya Dileep Kurdekar ◽

L. A. Avinash Chunduri ◽

C. Sai Manohar ◽

Mohan Kumar Haleyurgirisetty ◽

Indira K. Hewlett ◽

...

Keyword(s):

Hiv Infection ◽

Limit Of Detection ◽

Gold Nanoclusters ◽

Enzyme Linked Immunosorbent Assay ◽

Dependent Manner ◽

Metal Nanoclusters ◽

Detection Range ◽

In Silico Studies ◽

P24 Antigen ◽

Hiv 1

We have engineered streptavidin-labeled fluorescent gold nanoclusters to develop a gold nanocluster immunoassay (GNCIA) for the early and sensitive detection of HIV infection. We performed computational simulations on the mechanism of interaction between the nanoclusters and the streptavidin protein via in silico studies and showed that gold nanoclusters enhance the binding to the protein, by enhancing interaction between the Au atoms and the specific active site residues, compared to other metal nanoclusters. We also evaluated the role of glutathione conjugation in binding to gold nanoclusters with streptavidin. As proof of concept, GNCIA achieved a sensitivity limit of detection of HIV-1 p24 antigen in clinical specimens of 5 pg/ml, with a detection range up to1000 pg/ml in a linear dose-dependent manner. GNCIA demonstrated a threefold higher sensitivity and specificity compared to enzyme-linked immunosorbent assay for the detection of HIV p24 antigen. The specificity of the immunoassay was 100% when tested with plasma samples negative for HIV-1 p24 antigen and positive for viruses such as hepatitis B virus, hepatitis C virus, and dengue. GNCIA could be developed into a universal labeling technology using the relevant capture and detector antibodies for the specific detection of antigens of various pathogens in the future.

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Dramatically Enhancing the Sensitivity of Immunoassay for Ochratoxin A Detection by Cascade-Amplifying Enzyme Loading

Toxins ◽

10.3390/toxins13110781 ◽

2021 ◽

Vol 13 (11) ◽

pp. 781

Author(s):

Zhuolin Song ◽

Lin Feng ◽

Yuankui Leng ◽

Mingzhu Huang ◽

Hao Fang ◽

...

Keyword(s):

Ochratoxin A ◽

Limit Of Detection ◽

High Sensitivity ◽

Cross Reaction ◽

Molar Ratio ◽

Quantitative Detection ◽

Enzyme Linked Immunosorbent Assay ◽

Enzyme Loading ◽

M13 Bacteriophage ◽

Mimic Peptide

Enzyme-linked immunosorbent assay (ELISA) is widely used in the routine screening of mycotoxin contamination in various agricultural and food products. Herein, a cascade-amplifying system was introduced to dramatically promote the sensitivity of an immunoassay for ochratoxin A (OTA) detection. Specifically, a biotinylated M13 bacteriophage was introduced as a biofunctional competing antigen, in which a seven-peptide OTA mimotope fused on the p3 protein of M13 was used to specifically recognize an anti-OTA monoclonal antibody, and the biotin molecules modified on capsid p8 proteins were used in loading numerous streptavidin-labeled polymeric horseradish peroxidases (HRPs). Owing to the abundance of biotinylated p8 proteins in M13 and the high molar ratio between HRP and streptavidin in streptavidin-polyHRP, the loading amount of HRP enzymes on the M13 bacteriophage were greatly boosted. Hence, the proposed method exhibited high sensitivity, with a limit of detection of 2.0 pg/mL for OTA detection, which was 250-fold lower than that of conventional ELISA. In addition, the proposed method showed a slight cross-reaction of 2.3% to OTB, a negligible cross-reaction for other common mycotoxins, and an acceptable accuracy for OTA quantitative detection in real corn samples. The practicability of the method was further confirmed with a traditional HRP-based ELISA method. In conclusion, the biotinylated bacteriophage and polyHRP structure showed potential as a cascade-amplifying enzyme loading system for ultra-trace OTA detemination, and its application can be extended to the detection of other analytes by altering specific mimic peptide sequences.

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Characterization and validation of fragment antigen-binding (Fab) antibody-based immunoassay for deoxymiroestrol, a potent phytoestrogen from Pueraria candollei

10.22541/au.161270515.50311593/v1 ◽

2021 ◽

Author(s):

Worapol Sae-foo ◽

Supaluk Krittanai ◽

Wipawee Juengsanguanpornsuk ◽

Gorawit Yusakul ◽

Tharita Kitisripanya ◽

...

Keyword(s):

Quantitative Method ◽

Estrogenic Activity ◽

Limit Of Detection ◽

Hormone Replacement ◽

Enzyme Linked Immunosorbent Assay ◽

Antigen Binding ◽

Pueraria Candollei ◽

Specific Determination ◽

Fragment Antigen Binding

Deoxymiroestrol is the most potent phytoestrogen in chromenes group that has been found in Pueraria candollei, Thai name known as Kwao Krua Khao. Several studies reported estrogenic activity of P. candollei in order to using as hormone replacement therapy for postmenopausal women. Previously, specific determination of deoxymiroestrol content by enzyme-linked immunosorbent assay (ELISA) using polyclonal antibody (pAb) have been reported. However, production of pAb has limitation and variability from different batches. Therefore, in this study, we established quantitative method for determination of deoxymiroestrol using fragment antigen-binding (Fab) antibody-based immunoassay. The developed immunoassay has specificity to deoxymiroestrol with a calibration range of 15.6-1000 ng mL-1. Precision including intra-assay and inter-assay are 1.48-7.11 and 0.58-9.31%, respectively. Accuracy of the assay showed in recovery between 99.77-101.61% when spike deoxymiroestrol standard into the samples. The limit of detection (LOD) is 30.80 ng mL-1. Comparation antibody-based immunoassay for determination of deoxymiroestrol using Fab with pAb was represented consistency (R2 = 0.9807) when analysis roots bark of Pueraria candollei from difference areas. Therefore, this development assay can apply to determine deoxymiroestrol content in the plant samples.

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Development of a Smartphone-Based Nanozyme-Linked Immunosorbent Assay for Quantitative Detection of SARS-CoV-2 Nucleocapsid Phosphoprotein in Blood

Frontiers in Microbiology ◽

10.3389/fmicb.2021.692831 ◽

2021 ◽

Vol 12 ◽

Author(s):

Bochao Liu ◽

Ze Wu ◽

Chaolan Liang ◽

Jinhui Lu ◽

Jinfeng Li ◽

...

Keyword(s):

Immunosorbent Assay ◽

Cross Reactivity ◽

Quantitative Detection ◽

Enzyme Linked Immunosorbent Assay ◽

Serum Samples ◽

Primary Screening ◽

Global Pandemic ◽

Novel Coronavirus ◽

Acid Test ◽

Control Samples

Since December 2019, a novel coronavirus (SARS-CoV-2) has resulted in a global pandemic of coronavirus disease (COVID-19). Although viral nucleic acid test (NAT) has been applied predominantly to detect SARS-CoV-2 RNA for confirmation diagnosis of COVID-19, an urgent need for alternative, rapid, and sensitive immunoassays is required for primary screening of virus. In this study, we developed a smartphone-based nanozyme-linked immunosorbent assay (SP-NLISA) for detecting the specific nucleocapsid phosphoprotein (NP) of SARS-CoV-2 in 37 serum samples from 20 COVID-19 patients who were diagnosed by NAT previously. By using SP-NLISA, 28/37 (75.7%) serum samples were detected for NP antigens and no cross-reactivity with blood donors’ control samples collected from different areas of China. In a control assay using the conventional enzyme-linked immunosorbent assay (ELISA), only 7/37 (18.91%) serum samples were detected for NP antigens and no cross-reactivity with control samples. SP-NLISA could be used for rapid detection of SARS-CoV-2 NP antigen in primary screening of SARS-CoV-2 infected individuals.

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