A Novel Immunoassay Test System for Detection of Modified Allergen Residues Present in Almond-, Cashew-, Coconut-, Hazelnut-, and Soy-Based Nondairy Beverages

2016 ◽  
Vol 79 (9) ◽  
pp. 1572-1582 ◽  
Author(s):  
JONGKIT MASIRI ◽  
LORA BENOIT ◽  
MAHZAD MESHGI ◽  
JEFFREY DAY ◽  
CESAR NADALA ◽  
...  
Keyword(s):  
Polyclonal Antibodies ◽  
Rapid Test ◽  
Test System ◽  
Food Samples ◽  
Cross Reactivity ◽  
Detection Methods ◽  
Robust Detection ◽  
Allergen Detection ◽  
Highly Sensitive ◽  
Milk Substitutes

ABSTRACT A growing number of plant-based milk substitutes have become commercially available, providing an array of options for consumers with dietary restrictions. Though several of these products rival cow's milk in terms of their nutritional profiles, beverages prepared with soy and tree nuts can be a significant concern to consumers because of potential contamination with food allergens. Adding to this concern is the fact that allergen residues from plant-based beverages are modified during manufacturing, thereby decreasing the sensitivity of antibody-based detection methods. Consequently, many commercially available allergen detection kits are less effective for allergens derived from nondairy milk substitutes. To address this limitation, we developed a panel of polyclonal antibodies directed against the modified proteins present in almond, cashew, coconut, hazelnut, and soy milks and incorporated them into rapid lateral flow immunoassay tests configured in both sandwich and competitive format. The tests had robust detection capabilities when used with a panel of various brand-name products, with a sensitivity of 1 ppm and selectivity values of 3 to 5 ppm in nondairy beverages. Minimal cross-reactivity to extracts prepared from common commodities was observed. The development of a highly sensitive and rapid test specifically designed to detect trace quantities of highly modified allergen residues in plant-based, dairy-free beverages will aid food manufacturers and regulatory agencies in monitoring products for these modified allergens when testing environmental and food samples.

Listeriolysin O-Based Latex Agglutination Test for the Rapid Detection of Listeria monocytogenes in Foods

1997 ◽  
Vol 60 (9) ◽  
pp. 1038-1040 ◽  
Author(s):  
GHASSAN M. MATAR ◽  
PEGGY S. HAYES ◽  
WILLIAM F. BIBB ◽  
BALA SWAMINATHAN
Keyword(s):  
Monoclonal Antibody ◽  
Listeria Monocytogenes ◽  
Rapid Detection ◽  
Rapid Test ◽  
Food Samples ◽  
Cross Reactivity ◽  
Latex Agglutination ◽  
Listeriolysin O ◽  
Agglutination Assay ◽  
Latex Beads

A latex agglutination-based test for the rapid detection of Listeria monocytogenes in foods was developed. An antilisteriolysin O (LLO) monoclonal antibody (HID5E12D7; IgG2b) covalently bound to polystyrene amidine-modified latex beads was used in a slide agglutination assay. The latex reagent detected 0.1 ng/ml of LLO in phosphate-buffered saline plus bovine serum albumin. It reacted with culture supernatants of L. monocytogenes but not with other Listeria species or Streptococcus groups A through G. The listeriolysin O latex agglutination assay (LLOLAT) was applied to 24-h and 48-h USDA primary enrichment cultures of 208 food samples obtained from refrigerators of listeriosis patients enrolled in a study to determine the role of foods in sporadic listeriosis. Of 19 samples positive by cultural techniques, 17 were positive by the LLOLAT. Cultures with low (<0.3 CFU/g) levels of L. monocytogenes were positive in the LLOLAT. No cross-reactivity occurred when using a heterogeneous monoclonal antibody. The LLOLAT is a sensitive, specific and rapid test and may be useful for screening foods for L. monocytogenes.

scholarly journals Narrow-Leafed Lupin Main Allergen β-Conglutin (Lup an 1) Detection and Quantification Assessment in Natural and Processed Foods

Foods ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 513 ◽  
Author(s):  
Elena Lima-Cabello ◽  
Juan D. Alché ◽  
Jose C. Jimenez-Lopez
Keyword(s):  
Food Industry ◽  
Food Samples ◽  
Cross Reactivity ◽  
Regulatory Agencies ◽  
Processed Food ◽  
Elisa Method ◽  
Efficient Management ◽  
Highly Sensitive ◽  
Analytical Tools ◽  
Detection And Quantification

The increasing prevalence of lupin allergy as a consequence to the functional characteristics of a growing number of sweet lupin-derived foods consumption makes the imperious necessity to develop analytical tools for the detection of allergen proteins in foodstuffs. The current study developed a new highly specific, sensitive and accurate ELISA method to detect, identify and quantify the lupin main allergen β-conglutin (Lup an 1) protein in natural and processed food. The implementation of accurate standards made with recombinant conglutin β1, and an anti-Lup an 1 antibody made from a synthetic peptide commonly shared among β-conglutin isoforms from sweet lupin species was able to detect up to 8.1250 ± 0.1701 ng (0.0406 ± 0.0009 ppm) of Lup an 1. This identified even lupin traces present in food samples which might elicit allergic reactions in sensitized consumers, such as β-conglutin proteins detection and quantification in processed (roasted, fermented, boiled, cooked, pickled, toasted, pasteurized) food, while avoiding cross-reactivity (false positive) with other legumes as peanut, chickpea, lentils, faba bean, and cereals. This study demonstrated that this new ELISA method constitutes a highly sensitive and reliable molecular tool able to detect, identify and quantify Lup an 1. This contributes to a more efficient management of allergens by the food industry, the regulatory agencies and clinicians, thus helping to keep the health safety of the consumers.

A Sandwich Enzyme-Linked Immunosorbent Assay for the Detection of Almonds in Foods†

2000 ◽  
Vol 63 (2) ◽  
pp. 252-257 ◽  
Author(s):  
JASON J. HLYWKA ◽  
SUSAN L. HEFLE ◽  
STEVE L. TAYLOR
Keyword(s):  
Immunosorbent Assay ◽  
Polyclonal Antibodies ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecylsulfate ◽  
Food Samples ◽  
Cross Reactivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Sesame Seeds ◽  
Quality Control Tool ◽  
Sandwich Type

An enzyme-linked immunosorbent assay was developed to detect almonds as potential allergenic contaminants in food. Polyclonal antibodies directed against roasted almonds were partially purified from immunized sheep and rabbits and used as capture and secondary antibodies, respectively, in a sandwich-type, 96-well plate format. Food samples and almond-spiked samples were extracted 1:10 in phosphate-buffered saline at 60°C for 2 h, centrifuged, and applied to wells coated with sheep anti-almond antibody. After incubation, washing, and the addition of rabbit anti-almond antibody, the amount of almond present was detected with the subsequent addition of goat anti-rabbit immunoglobulin G–alkaline phosphatase conjugate and p-nitrophenyl phosphate substrate. Plate absorbances were read at 410 nm, and standard curves were developed in all matrices to quantify unknowns. Antibodies developed were specific for almond; however, some cross-reactivity was observed with extracts of some tree nuts and sesame seeds. Sodium dodecylsulfate–polyacrylamide gel electrophoresis and Western immunoblotting indicated that sheep anti-almond antibody recognized proteins extracted from black walnuts, Brazil nuts, cashews, hazelnuts, macadamia nuts, pistachios, and sesame seeds in addition to those from almond. The assay was optimized to detect less than 1 ppm of almond and was used successfully to determine almond residues in cereal and chocolate without cross-reacting interferences. A retail survey of 20 brands of cereal demonstrated that the assay produced statistically consistent results. This assay provides a useful quality control tool for the food industry for the protection of consumers allergic to almonds.

scholarly journals Use of a Heterologous Bridge Coating Antigen for the Immunoassay of 3-Acetyldeoxynivalenol in Barley

1996 ◽  
Vol 59 (5) ◽  
pp. 525-532 ◽  
Author(s):  
NA WANG ◽  
DANUTA KIEREK-JASZCZUK ◽  
RONALD R. MARQUARDT ◽  
ANDREW A. FROHLICH ◽  
DAVID ABRAMSON
Keyword(s):  
Polyclonal Antibodies ◽  
Cross Reactivity ◽  
Competitive Elisa ◽  
Enzyme Linked Immunosorbent Assay ◽  
Trichothecene Mycotoxin ◽  
Ether Linkage ◽  
Low Concentrations ◽  
Highly Sensitive ◽  
Ester Linkage ◽  
Inhibition Curve

The study describes procedures that were used to develop a highly sensitive enzyme-linked immunosorbent assay (ELISA) for the quantitation of a trichothecene mycotoxin, 3-acetyldeoxynivalenol (3-AcDON), in barley. Polyclonal antibodies were produced in rabbits immunized with a conjugate of 3-AcDON and human serum albumin linked by an ester linkage (hemisuccinate bridge). High anti-3-AcDON titers were obtained after multiple immunizations. However, only a negligible degree of inhibition was obtained with 3-AcDON in a competitive ELISA when the coating conjugate contained the same ester linkage group (hemiglutarate bridge) as the immunogen. The use of a conjugate containing a heterologous ether linkage (O-methylcarboxyl bridge) compared to that of the immunogen yielded an inhibition curve for 3-AcDON that was highly sensitive (IC50 = 0.21 ng/ml) with essentially no interference from the bridging group. This conjugate was synthesized using iodoacetate and 1,1′-carbonyldiimidazole chemistries. The assay showed low cross-reactivity with other trichothecenes including several analogs of deoxynivalenol (DON) with the exception of acetylated DON. The ELISA developed on the basis of this new conjugate was able to detect low concentrations of 3-AcDON (16 ppb) in spiked barley without any cleanup treatments.

Highly sensitive immunoenzymometric assay for human thyrotropin.

1985 ◽  
Vol 31 (4) ◽  
pp. 634-636 ◽  
Author(s):  
Y Watanabe ◽  
N Amino ◽  
H Tamaki ◽  
M Aozasa ◽  
J Tachi ◽  
...  
Keyword(s):  
Polyclonal Antibodies ◽  
Normal Subjects ◽  
Normal Pregnancy ◽  
Cross Reactivity ◽  
Sensitive Assay ◽  
Serum Samples ◽  
Human Choriogonadotropin ◽  
Assay Procedure ◽  
Analytical Recovery ◽  
Highly Sensitive

Abstract A sensitive assay procedure for immunoenzymometric assay of serum thyrotropin (TSH) was developed by making several modifications of the Enzymun-Test TSH kit (Boehringer, Mannheim GmbH). Serum samples were first incubated in plastic tubes precoated with monoclonal antibodies specific to the beta subunit of human TSH. After the tubes were washed, the TSH bound to the tubes was detected with peroxidase-conjugated polyclonal antibodies to TSH. The sensitivity of the assay was 0.2 milli-int. unit/L, and the intra-and interassay CVs were less than 10%. Analytical recovery was 96 to 106%. The normal basal range of TSH was 0.5 to 4.8 milli-int. units/L. The basal levels of TSH in all but one of 48 thyrotoxic patients with Graves' disease were less than 0.2 milli-int. unit/L, clearly different from those of normal subjects. Thyrotoxic patients in early normal pregnancy showed TSH concentrations of 1.7 to 2.9 milli-int. units/L by conventional double-antibody radioimmunoassay, possibly from cross reactivity with human choriogonadotropin, but undetectable TSH by this method. Measurement of basal TSH by this sensitive assay can be used as an initial screening test for thyroid dysfunction.

scholarly journals Food Sensing: Detection of Bacillus cereus Spores in Dairy Products

Biosensors ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 15 ◽  
Author(s):  
Jasmina Vidic ◽  
Carole Chaix ◽  
Marisa Manzano ◽  
Marc Heyndrickx
Keyword(s):  
Bacillus Cereus ◽  
Dairy Products ◽  
Food Samples ◽  
Detection Methods ◽  
Economic Losses ◽  
Processing Plant ◽  
Advantages And Disadvantages ◽  
Microbiological Methods ◽  
Highly Sensitive ◽  
Highly Sensitive Detection

Milk is a source of essential nutrients for infants and adults, and its production has increased worldwide over the past years. Despite developments in the dairy industry, premature spoilage of milk due to the contamination by Bacillus cereus continues to be a problem and causes considerable economic losses. B. cereus is ubiquitously present in nature and can contaminate milk through a variety of means from the farm to the processing plant, during transport or distribution. There is a need to detect and quantify spores directly in food samples, because B. cereus might be present in food only in the sporulated form. Traditional microbiological detection methods used in dairy industries to detect spores show limits of time (they are time consuming), efficiency and sensitivity. The low level of B. cereus spores in milk implies that highly sensitive detection methods should be applied for dairy products screening for spore contamination. This review describes the advantages and disadvantages of classical microbiological methods used to detect B. cereus spores in milk and milk products, related to novel methods based on molecular biology, biosensors and nanotechnology.

Development of an antigen-ELISA and a colloidal gold–based immunochromatographic strip based on monoclonal antibodies for detection of avian influenza A(H5) viruses

2021 ◽  
pp. 104063872110275
Author(s):  
Yixin Xiao ◽  
Fan Yang ◽  
Fumin Liu ◽  
Linfang Cheng ◽  
Hangping Yao ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Disease Virus ◽  
Colloidal Gold ◽  
Rapid Detection ◽  
Influenza A ◽  
Field Investigation ◽  
Cross Reactivity ◽  
Detection Methods ◽  
Immunochromatographic Strip ◽  
Antigen Elisa

Avian influenza A(H5) viruses (avian IAVs) pose a major threat to the economy and public health. We developed an antigen-ELISA (ag-ELISA) and a colloidal gold–based immunochromatographic strip for the rapid detection of avian A(H5) viruses. Both detection methods displayed no cross-reactivity with other viruses (e.g., other avian IAVs, infectious bursal disease virus, Newcastle disease virus, infectious bronchitis virus, avian paramyxovirus). The ag-ELISA was sensitive down to 0.5 hemagglutinin (HA) units/100 µL of avian A(H5) viruses and 7.5 ng/mL of purified H5 HA proteins. The immunochromatographic strip was sensitive down to 1 HA unit/100 µL of avian A(H5) viruses. Both detection methods exhibited good reproducibility with CVs < 10%. For 200 random poultry samples, the sensitivity and specificity of the ag-ELISA were 92.6% and 98.8%, respectively, and for test strips were 88.9% and 98.3%, respectively. Both detection methods displayed high specificity, sensitivity, and stability, making them suitable for rapid detection and field investigation of avian A(H5) viruses.

Detection by real-time quaking-induced conversion (RT-QuIC), ELISA, and IHC of chronic wasting disease prion in lymph nodes from Pennsylvania white-tailed deer with specific PRNP genotypes

2021 ◽  
pp. 104063872110214
Author(s):  
Deepanker Tewari ◽  
David Steward ◽  
Melinda Fasnacht ◽  
Julia Livengood
Keyword(s):  
Real Time ◽  
Disease Susceptibility ◽  
Chronic Wasting Disease ◽  
Low Frequency ◽  
The United States ◽  
Detection Methods ◽  
Spongiform Encephalopathy ◽  
Wasting Disease ◽  
Diagnostic Laboratory ◽  
Highly Sensitive

Chronic wasting disease (CWD) is a prion-mediated, transmissible disease of cervids, including deer ( Odocoileus spp.), which is characterized by spongiform encephalopathy and death of the prion-infected animals. Official surveillance in the United States using immunohistochemistry (IHC) and ELISA entails the laborious collection of lymphoid and/or brainstem tissue after death. New, highly sensitive prion detection methods, such as real-time quaking-induced conversion (RT-QuIC), have shown promise in detecting abnormal prions from both antemortem and postmortem specimens. We compared RT-QuIC with ELISA and IHC for CWD detection utilizing deer retropharyngeal lymph node (RLN) tissues in a diagnostic laboratory setting. The RLNs were collected postmortem from hunter-harvested animals. RT-QuIC showed 100% sensitivity and specificity for 50 deer RLN (35 positive by both IHC and ELISA, 15 negative) included in our study. All deer were also genotyped for PRNP polymorphism. Most deer were homozygous at codons 95, 96, 116, and 226 (QQ/GG/AA/QQ genotype, with frequency 0.86), which are the codons implicated in disease susceptibility. Heterozygosity was noticed in Pennsylvania deer, albeit at a very low frequency, for codons 95GS (0.06) and 96QH (0.08), but deer with these genotypes were still found to be CWD prion-infected.

scholarly journals Probe-Based Real-Time qPCR Assays for a Reliable Differentiation of Capripox Virus Species

2021 ◽  
Vol 9 (4) ◽  
pp. 765
Author(s):  
Janika Wolff ◽  
Martin Beer ◽  
Bernd Hoffmann
Keyword(s):  
Real Time ◽  
Animal Health ◽  
Diagnostic Methods ◽  
Virus Species ◽  
Time Saving ◽  
Robust Detection ◽  
Highly Sensitive ◽  
Reliable Differentiation ◽  
World Organization ◽  
Real Time Qpcr

Outbreaks of the three capripox virus species, namely lumpy skin disease virus, sheeppox virus, and goatpox virus, severely affect animal health and both national and international economies. Therefore, the World Organization for Animal Health (OIE) classified them as notifiable diseases. Until now, discrimination of capripox virus species was possible by using different conventional PCR protocols. However, more sophisticated probe-based real-time qPCR systems addressing this issue are, to our knowledge, still missing. In the present study, we developed several duplex qPCR assays consisting of different types of fluorescence-labelled probes that are highly sensitive and show a high analytical specificity. Finally, our assays were combined with already published diagnostic methods to a diagnostic workflow that enables time-saving, reliable, and robust detection, differentiation, and characterization of capripox virus isolates.

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.

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