scholarly journals Detection of Brevetoxin in Human Plasma by ELISA

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.

scholarly journals Highly Specific Chemiluminescence Immunoassay for the Determination of Chloramphenicol in Cosmetics

2019 ◽  
Vol 2019 ◽  
pp. 1-6
Author(s):  
Qiyan Li ◽  
Riran Zhu ◽  
Jun Li ◽  
Xiaobing Wang ◽  
Lihua Xu ◽  
...  
Keyword(s):  
Quality Control ◽  
Limit Of Detection ◽  
Cross Reactivity ◽  
Quantitative Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Elisa Method ◽  
Chemiluminescence Immunoassay ◽  
Detection Range ◽  
Direct Immunoassay

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.

scholarly journals Preconcentration and Detection of Gefitinib Anti-Cancer Drug Traces from Water and Human Plasma Samples by Means of Magnetic Nanoparticles

Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1196 ◽  
Author(s):  
Hadeer Borg ◽  
Dániel Zámbó ◽  
Heba Elmansi ◽  
Heba M. Hashem ◽  
Jenny Jehan Nasr ◽  
...  
Keyword(s):  
Particle Size ◽  
Magnetic Nanoparticles ◽  
Human Plasma ◽  
Cancer Drug ◽  
Quantitative Detection ◽  
Plasma Samples ◽  
Widespread Application ◽  
Human Plasma Samples ◽  
Relative Standard ◽  
Anti Cancer

Along of widespread application of anti-cancer drug Gefitinib (GEF), it appears in human body fluids as well as clinical wastewater. Consequently, a reliable and easy-to-adapt detection technique is of essential importance to quantify the drug in different media. The extraction and quantitative detection of anti-cancer drug Gefinitib (GEF) is demonstrated based on a straightforward and efficient magnetic nanoparticle-assisted preconcentration route from water and human plasma samples. Iron oxide magnetic nanoparticles (Fe3O4) have been prepared with an average particle size of 15 nm and utilized as extractible adsorbents for the magnetic solid-phase extraction (MSPE) of GEF in aqueous media. The method is based on MSPE and preconcentration of GEF followed by High-Performance Liquid Chromatography-Ultraviolet Detection (HPLC-UV). The yield of GEF extraction under the optimum MSPE conditions were 94% and 87% for water and plasma samples, respectively. The chromatographic separation was carried out isocratically at 25 °C on a Phenomenex C8 reversed phase column (150 mm × 4.6 mm, with 5 µm particle size). The proposed method was linear over concentration ranges of 15.0–300.0 and 80.0–600.0 ng/mL for water and plasma samples with limits of detection of 4.6 and 25.0 ng/mL in a respective order. Relative standard deviations (%RSD) for intra-day and inter-day were 0.75 and 0.94 for water samples and 1.26 and 1.70 for plasma samples, respectively. Using the magnetic nanoparticles (MNPs) as loaded drug-extractors made the detection of the anti-cancer drug environmentally friendly and simple and has great potential to be used for different drug-containing systems.

scholarly journals A highly sensitive octopus-like azobenzene fluorescent probe for determination of abamectin B1 in apples

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhenlong Guo ◽  
YiFei Su ◽  
Kexin Li ◽  
MengYi Tang ◽  
Qiang Li ◽  
...  
Keyword(s):  
Fluorescent Probe ◽  
Limit Of Detection ◽  
Quantitative Detection ◽  
Fluorescence Signal ◽  
Ionization Mass ◽  
Limit Of Quantification ◽  
Visible Absorption ◽  
Esi Ms ◽  
Relative Standard ◽  
Ft Ir

AbstractThe development of detecting residual level of abamectin B1 in apples is of great importance to public health. Herein, we synthesized a octopus-like azobenzene fluorescent probe 1,3,5-tris (5′-[(E)-(p-phenoxyazo) diazenyl)] benzene-1,3-dicarboxylic acid) benzene (TPB) for preliminary detection of abamectin B1 in apples. The TPB molecule has been characterized by ultraviolet–visible absorption spectrometry, 1H-nuclear magnetic resonance, fourier-transform infrared (FT-IR), electrospray ionization mass spectroscopy (ESI-MS) and fluorescent spectra. A proper determination condition was optimized, with limit of detection and limit of quantification of 1.3 µg L−1 and 4.4 μg L−1, respectively. The mechanism of this probe to identify abamectin B1 was illustrated in terms of undergoing aromatic nucleophilic substitution, by comparing fluorescence changes, FT-IR and ESI-MS. Furthermore, a facile quantitative detection of the residual abamectin B1 in apples was achieved. Good reproducibility was present based on relative standard deviation of 2.2%. Six carboxyl recognition sites, three azo groups and unique fluorescence signal towards abamectin B1 of this fluorescent probe demonstrated reasonable sensitivity, specificity and selectivity. The results indicate that the octopus-like azobenzene fluorescent probe can be expected to be reliable for evaluating abamectin B1 in agricultural foods.

scholarly journals Antibody Microarray Immunoassay for Simultaneous Quantification of Multiple Mycotoxins in Corn Samples

Toxins ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 415 ◽  
Author(s):  
Xian Zhang ◽  
Zuohuan Wang ◽  
Yun Fang ◽  
Renjie Sun ◽  
Tong Cao ◽  
...  
Keyword(s):  
Ochratoxin A ◽  
Aflatoxin B1 ◽  
Goodness Of Fit ◽  
Limit Of Detection ◽  
Simultaneous Detection ◽  
Fumonisin B1 ◽  
Quantitative Detection ◽  
Antibody Microarray ◽  
Test Kit ◽  
Microarray Immunoassay

We developed and tested a prototype of an antibody microarray immunoassay for simultaneous quantitative detection of four typical mycotoxins (aflatoxin B1, ochratoxin A, zearalenone, and fumonisin B1) in corn samples. The test kit consisted of a nitrocellulose membrane layered with immobilized monoclonal antibodies against mycotoxins. During the assay, the mycotoxin-protein conjugates were biotinylated. The signal detection was enhanced by a combination of the biotin-streptavidin system and enhanced chemiluminescence (ECL). This improved the sensitivity of the assay. Under the optimized conditions, four calibration curves with goodness of fit (R2 > 0.98) were plotted. The results showed that the detection limits for aflatoxin B1, ochratoxin A, zearalenone, and fumonisin B1 were 0.21, 0.19, 0.09, and 0.24 ng/mL, with detection ranges of 0.47–55.69, 0.48–127.11, 0.22–31.36, and 0.56–92.57 ng/mL, respectively. The limit of detection (LOD) of this antibody microarray for aflatoxin B1, ochratoxin A, zearalenone, and fumonisin B1 in corn was 5.25, 4.75, 2.25, and 6 μg/kg, respectively. The recovery rates from the spiked samples were between 79.2% and 113.4%, with coefficient of variation <10%. The results of the analysis of commercial samples for mycotoxins using this new assay and the liquid chromatography-tandem mass spectrometry (LC-MS/MS) were comparable and in good agreement. This assay could also be modified for the simultaneous detection of other multiple mycotoxins, as well as low-weight analytes, hazardous to human health.

Preliminary validation of two novel immunoassays for detecting VEGF in human and mouse plasma using single molecule counting technology

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. e22099-e22099
Author(s):  
R. Puskas ◽  
D. Held ◽  
D. Sheets ◽  
B. K. Klein ◽  
E. Macy ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Human Plasma ◽  
Plasma Cell ◽  
Cross Reactivity ◽  
Conditioned Media ◽  
Elisa Assay ◽  
Plasma Samples ◽  
Preliminary Validation ◽  
Tissue Specimens ◽  
Human And Mouse

e22099 Background: Growth in biomarkers as therapeutic targets and as surrogate markers for efficacy presents a need for increasingly sensitive immunoassays to expand biomarker applicability. Improved immunoassays will provide: (1) better evaluation and validation of new drug candidates, (2) better matching of patients to new therapies, (3) accelerated drug approval (4) earlier diagnosis of at-risk patients, and (5) a deeper understanding of cancer biology. Towards this end, Singulex has developed two ultra- sensitive VEGF Immunoassays for human and mouse vascular endothelial growth factor (VEGF). Here we report the preliminary validation of these two novel assays. Methods: Two novel assays were developed with the Erenna Immunoassay System for detecting VEGF: human (hVEGF) and mouse (mVEGF). Analytical sensitivity, cross-reactivity and precision were determined and compared to an ELISA based VEGF assay. Both the Singulex assay and ELISA assay were used to test a range of specimen types (plasma, cell lysates, conditioned media, and tissue specimens) from humans and mice. Preliminary assays with human plasma and tissue specimens were conducted to compare hVEGF levels between normal and breast cancer samples. Results: The Singulex hVEGF assay had an LOD of 0.1 pg/mL, an LLOQ of 0.3 pg/mL, and 84–107% spike recovery; 90X more sensitive than the ELISA assay. Human VEGF concentrations were quantified in all specimens tested compared to the ELISA, which quantified VEGF in only 8% of plasma samples, but all of the cell lysate samples. The Singulex mVEGF assay had an LOD of 3.5 pg/mL, LLOQ of 5 pg/mL, and 68–111% spike recovery; 3X more sensitive than the ELISA assay. Cross-reactivity for the two assays was minimal for all specimen types tested, except for human plasma samples where the mVEGF assay demonstrated 80–100% CR. Conclusions: We show that the Singulex hVEGF and mVEGF Immunoassays can detect VEGF at or below pg/mL levels, and can effectively quantify VEGF levels in plasma, cell lysates, conditioned media, and tissue samples from mice and humans. These novel assays are an important tool when used to assess tumor and normal breast cancer tissue and plasma. [Table: see text]

Validation of MAX Aqueous Extraction on Veratox® for Total Aflatoxin ELISA Test Kit

2017 ◽  
Vol 100 (4) ◽  
pp. 1131-1133 ◽  
Author(s):  
Brooke E Roman ◽  
Dana Driksna ◽  
Mohamed M Abouzied ◽  
Frank Klein ◽  
Jennifer Rice
Keyword(s):  
Reference Material ◽  
Organic Solvents ◽  
Validation Studies ◽  
Extraction Method ◽  
Elisa Test ◽  
Cross Reactivity ◽  
Aqueous Extraction ◽  
Total Aflatoxin ◽  
Detection Range ◽  
Test Kit

Abstract Neogen Corp. (Lansing, MI) has developed a common aqueous extraction method for the detection of mycotoxins in the ELISA or lateral flow format. The Veratox® for Total Aflatoxin ELISA extraction method uses a MAX 2 extraction packet and water in replacement of traditionally used organic solvents. Veratox for Total Aflatoxin has a detection range of 5–50 ppb neat or up to 300 ppb with dilution. The kit development focused on superior cross-reactivity, ability to accurately detect naturally contaminated samples, and utilization of an aqueous extraction method. In two separate validation studies, the Veratox for Total Aflatoxin test kit resulted in average yields of 91–114% in naturally contaminated mycotoxin reference material corn. The cross-reactivity profiles for aflatoxins B1, B2, G1, and G2 were 100, 113, 103, and 93%, respectively. This kit is approved by the Grain Inspection, Packers, and Stockyards Administration.

scholarly journals Europium Fluorescent Nanoparticles-Based Multiplex Lateral Flow Immunoassay for Simultaneous Detection of Three Antibiotic Families Residue

2021 ◽  
Vol 9 ◽  
Author(s):  
Yaping Wang ◽  
Biao Ma ◽  
Miaomiao Liu ◽  
Erjing Chen ◽  
Ying Xu ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Quantitative Analysis ◽  
Uv Light ◽  
Simultaneous Detection ◽  
Rapid Screening ◽  
Quantitative Detection ◽  
Fluorescent Nanoparticles ◽  
Antibiotic Residues ◽  
Detection Range ◽  
Relative Standard

A fluorescent immunoassay based on europium nanoparticles (EuNPs-FIA) was developed for the simultaneous detection of antibiotic residues, solving the problems of single target detection and low sensitivity of traditional immunoassay methods. In the EuNPs-FIA, EuNPs were used as indictive probes by binding to anti-tetracyclines monoclonal antibodies (anti-TCs mAb), anti-sulphonamides monoclonal antibodies (anti-SAs mAb) and anti-fluoroquinolones monoclonal antibodies (anti-FQs mAb), respectively. Different artificial antigens were assigned to different regions of the nitrocellulose membrane as capture reagents. The EuNPs-FIA allowed for the simultaneous detection of three classes of antibiotics (tetracyclines, fluoroquinolones and sulphonamides) within 15 min. It enabled both the qualitative determination with the naked eye under UV light and the quantitative detection of target antibiotics by scanning the fluorescence intensity of the detection probes on the corresponding detection lines. For qualitative analysis, the cut-off values for tetracyclines (TCs), fluoroquinolones (FQs) and sulphonamides (SAs) were 3.2 ng/ml, 2.4 ng/ml and 4.0 ng/ml, respectively, which were much lower than the maximum residue limit in food. For quantitative analysis, these ranged from 0.06 to 6.85 ng/ml for TCs, 0.03–5.14 ng/ml for FQs, and 0.04–4.40 ng/ml for SAs. The linear correlation coefficients were higher than 0.97. The mean spiked recoveries ranged from 92.1 to 106.2% with relative standard deviations less than 8.75%. Among them, the three monoclonal antibodies could recognize four types of TCs, seven types of FQs and 13 types of SAs, respectively, and the detection range could cover 24 antibiotic residues with different structural formulations. The results of the detection of antibiotic residues in real samples using this method were highly correlated with those of high performance liquid chromatography (R2 &gt; 0.98). The accuracy and precision of the EuNPs-FIA also met the requirements for quantitative analysis. These results suggested that this multiplex immunoassay method was a promising method for rapid screening of three families of antibiotic residues.

scholarly journals Microextraction by Packed Molecularly Imprinted Polymer Combined Ultra-High-Performance Liquid Chromatography for the Determination of Levofloxacin in Human Plasma

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Jia Meng ◽  
Xu Wang
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Human Plasma ◽  
Bacterial Infections ◽  
High Performance ◽  
Limit Of Detection ◽  
Binding Capacity ◽  
Molecularly Imprinted ◽  
Relative Standard

Fluoroquinolones are considered as gold standard for the prevention of bacterial infections. To improve assessment of antibacterial efficacy, a novel method for determination of levofloxacin was developed and validated. Deep eutectic solvents (DESs) as only green solvent were used as a porogen for preparation of water-compatible molecularly imprinted polymers (MIPs) with a pseudotemplate. The DESs-MIPs were characterized in detail, including scanning electron microscope, nitrogen sorption porosimetry, and Fourier transform-infrared spectra. Clearly, the maximum binding capacity of levofloxacin on DESs-MIPs in water and methanol was 0.216 and 0.077 μmol g−1, respectively. The DESs-MIPs as adsorbing materials were applied in microextraction by packed sorbent (MEPS), and the DESs-MIPs-MEPS conditions were optimized. The DESs-MIPs-MEPS coupled with ultra-high-performance liquid chromatography (UHPLC) was used to determine levofloxacin in human plasma. The method was found linear over 0.05–10 μg mL−1 with coefficient of correlation equal to 0.9988. The limit of detection and limit of quantification were 0.012 and 0.04 μg mL−1, respectively. At three spiked levels, the precision of proposed method was between 95.3% and 99.7% with intraday and interday relative standard deviations ≤8.9%. Finally, the developed method was used to examine levofloxacin from human plasma of 20 hospitalized patients after transrectal ultrasound-guided prostate biopsy, and the average concentration (±SD) of levofloxacin was 2.35 ± 0.99 μg mL−1 in plasma.

Vortex-Assisted Dispersive Liquid–Liquid Microextraction Coupled with Deproteinization for Determination of Nateglinide in Human Plasma Using HPLC/UV

2020 ◽  
Author(s):  
Mohamed A Hammad ◽  
Amira H Kamal ◽  
Reham E Kannouma ◽  
Fotouh R Mansour
Keyword(s):  
Human Plasma ◽  
High Performance ◽  
Limit Of Detection ◽  
Signal To Noise Ratio ◽  
Cost Effective ◽  
Salt Addition ◽  
Relative Standard ◽  
Dispersive Liquid Liquid Microextraction ◽  
Liquid Microextraction

Abstract A validated method for preconcentration and determination of nateglinide in plasma was developed using vortex-assisted dispersive liquid–liquid microextraction. Different variables that affect extraction efficiency were studied and optimized, including type and volume of extractant, type and volume of disperser, pH of diluent, salt addition effect, centrifugation and vortex time. Nateglinide was extracted using 30 μL of 1-octanol as an extractant and 200 μL of methanol as a disperser. The enrichment factor reached 330 under the optimum conditions. High-performance liquid chromatography/ultraviolet was used for detection using phosphate buffer (pH 2.5, 10 mM): acetonitrile (45:55, v/v) as a mobile phase at a flow rate of 1 mL/min. The method was linear over the range of 50–20,000 ng/mL with a limit of detection of 15 ng/mL (signal-to-noise ratio = 3). Intra- and inter-day precision had %relative standard deviation &lt;6% (n = 3) and the %recoveries were found to be between 102.5 and 105.9%. The proposed method is simple, sensitive, eco-friendly, cost-effective and powerful for microextraction of nateglinide from human plasma samples.

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

2007 ◽  
Vol 90 (4) ◽  
pp. 1000-1010 ◽  
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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